Gods Need Prayer Badly

""They were Gods once, but their worshipers either died out or were converted to the worship of other Gods. They wail and flutter around the edges of reality without substance or even thought. All they have is need. ... We go out of fashion, Sparhawk--like last year's gowns or old shoes and hats. The Powerless Ones are discarded Gods who shrink and shrink as the years go by until they're finally nothing at all but a kind of anguished wailing.""

- The Goddess Aphrael

In the world of Fantasy, it is a largely accepted fact that the power of any given deity is proportional to the amount of belief in them or the amount of worship they are currently receiving.

Possibly, the deity was originally conceived and shaped by the needs and desires of one small group. But like any good Me Me, this 'idea' grows with each new person who responds, then spreads the word of this great new 'god on the block'. Soon, the deity has enough collective belief behind their 'name brand' that they actually come into existence, and use that power to fulfil the needs of their worshippers.

But the opposite is also true: As a deity's power base of worshippers shrinks, their divine strength fades; if all worship of them ceases, they may completely fade out of existence in a Puff of Logic. The tragedy here is that worshippers who leave the god because he/she didn't grant their miracle will continuously weaken the god until they can't grant any miracles. Kind of like a bank run on a god.

In a similar manner, the well-being of an Anthropomorphic Personification is often tied to whatever concept they personify. Big concepts like Fate or Death are pretty safe, but Disco is in critical condition.

A subtrope of Clap Your Hands If You Believe, which can be used to explain why The Powers That Be care whether or not anyone worships them. Or in games where you play as a Physical God, this is often used as a game mechanic to explain why you can't just Deus Ex Machina your way through everything. It can also be used by authors as a Take That against organized religion. Compare I'm Not Afraid of You, where smaller Anthropomorphic Personifications can be disbelieved.

Depending on the setting, of course, the gods can often provide incentives for people to worship them. The gods of most typical Dungeons & Dragons settings grant divine spells to their priests, which give them all kinds of fancy powers. Mortals and gods end up in a symbiotic relationship, with the humans providing belief and worship to the gods and the gods providing assorted divine miracles in return.

This trope is related to Emotion Eater, but doesn't imply evil, vampirism, or even negative emotions unless the god is tied in with those by nature. In belief systems of this kind, the empowered god often gives power back to his worshipers. Contrast Stop Worshipping Me!, for when the god hates the worship they do get.

This trope is of course dependent on a Physical Religion to entice prayer in the first place.

Named for Gauntlet (1985 video game)'s " needs food, badly!" catchphrase.

Anime and Manga

 * Very important in Kannagi. As traditional faith dwindled the sisters have been losing their powers to the point where they are fighting over the remaining faith power. Nagi's sacred tree which once sustained her has been cut down, and Zange's is inside a church, further dwindling / altering their powers and conditions. Zange has been taking on Christian aspects and resorting to setting herself up as a pop star to gain "faith" in the form of fans. The more believers they get, the more powerful they become.
 * In the end of Pita-Ten it is revealed that angels' and demons' existence depends on human faith in them, and once some entity is forgotten it ceases to exist which is a way to kill demon or angel, however if memory is restored it is possible to revive a dead demon or angel. Strangely enough these virtual creatures have quite strong real powers and can manipulate human memory as well.
 * In the Slayers world, the dragon gods gain strength from praise and worship, which is in contrast to the opposing Mazoku who feed on human suffering. This plays a role in a war between one of the gods and the Mazoku race that occurs a thousand years in the past from Lina's time. The Mazoku crippled the Water Dragon King by killing all the worshipers and destroying all the temples dedicated to the latter.
 * The second episode of Natsume Yuujinchou has a very poignant example of this trope (that also doubles as a Tear Jerker) when a Youkai that took up residence in a roadside shrine begins to lose his power (and his tether to the living world) as the people who once prayed to him all begin to die of old age. Natsume himself offers to pray to him but the Youkai refuses saying: "It's impossible, because you are my friend."
 * A key theme in Serial Experiments Lain; defines godhood as this, and the main thrust of his scheme is ensuring he will have people believe him to be God, so that for all intents and purposes he will be.
 * Fanon of Axis Powers Hetalia has it that the Nations are born when their national identity begins to develop, and "die" when no one identifies with them anymore.
 * Shown in Nurarihyon no Mago when Senba, a god of healing, feared he would fade away and disappear because no one visted his shrine anymore.
 * One chapter of Franken Fran shows the point when the Flying Spaghetti Monster finally gets enough worshipers to become real because of this trope. FF being the kind of manga it is, it manifests by absorbing several of its followers into a single hideous mass.

Comic Books

 * Very, very, very Depending on the Writer in both The DCU and the Marvel Universe. Sometimes the gods complain about this, sometimes they draw plenty of power from the ideas they're embodiments of even if people don't know about the Anthropomorphic Personifications as people, sometimes they flat don't care.
 * In general this applies more to DC than Marvel. In Marvel the abstracts are not usually called gods and transcend them. More traditional gods like Thor and Ares have not been worshiped on a wide scale for centuries. They don't complain about loss of power or seek out new worshipers. They show no loss of power over time. Some writers have shown a connection between mortals and gods, but generally this is more a cultural connection that allows gods to interact on Earth instead of a dependency on faith.
 * DC gods tend to be more vulnerable to this. It is usually use to justify Ares being a major threat to even the combined Olympian gods and why he constantly spreads war. Several storylines have had Ares and other gods be stronger than Zeus due to changes in worship and things mortals venerate. A lot less people are afraid of the sky or praying for rain than they used too. However, power tends to rely less on direct worship and more on how important the concept a god represents is to the mortal world. Ares can feed on conflict of any kind instead of that just dedicated to him. There are exceptions. The New Gods tend to stay strong without a race to draw strength from, but at times they have implied to be more gods of technology that draw power from across the universe.
 * In fact, New God Orion was very emphatic about this in his series - when rather pathetically confronted by a defeated enemy with this notion, he replied "You have been reading too much fiction. Gods are not dependent on their worshipers - worshipers are dependent on their gods."
 * In the Fear Itself crossover, Iron Man mocks, invokes, and turns this into one helluva Tear Jerker. He started screaming at Odin and the other gods (but mostly Odin), yelling that if they wanted a sacrifce he'd give them the "only thing he could give worth anything": his sobriety, by taking a huge swig of alcohol. Even though it was a Narm scene, it was effective to the fans who know how hard he works to stay sober.
 * DC perhaps most notably has this apply to a modern-day god of recent birth, Uncle Sam, whose power is directly proportional to the American People's belief in freedom and liberty. Whether American protecterates like Puerto Rico, Guam, and the Virgin Islands' people's belief in freedom and liberty counts towards this is never specified.
 * The Sandman had gods born from dreams and when they were forgotten they would return to the world of dreams to eventually fade away. Lucifer followed a similar idea. The goddess Bast is a shadow of her former shelf. Ishtar had to become a stripper. The Japanese gods absorb articles of faith from other pantheons and modern times to survive. The Norse gods appear to be doing pretty well though.
 * In fact, Neil Gaiman frequently reminded readers that The Endless are not gods, because they do not care if they are remembered and will persist long after humanity is gone. They really are Death, Dream, Despair etc, and their existence depends on these aspects of the universe rather than mythology, and not just on Earth.
 * In Knights of the Dinner Table, after Bob's character, Knuckles III, dies, his next character (Knuckles IV) manages to get Knuckles III promoted to gawdhood. Temples to Knu-Kyle-Ra are now a recurring feature in the comic. Unfortunately, they don't owe Bob's other characters any favors.
 * In My Faith In Frankie, gods gain power from the belief of their followers. Judging by Jeriven, they only need one true believer to be at full strength, but more may have more effect.
 * In one of the later Savage Sword of Conan comics, Conan's physical likeness to a hero-turned-demigod is exploited by a local tyrant looking to put down a growing rebellion and win droves of recruits to his army. (Said hero, Shan, had once promised to return to his people one day when their suffering became intolerable.) This becomes problematic when the actual demigod shows up on the battlefield and strikes down everyone who participated in the fraud, except Conan. Impressed by his bravado, Shan decides to slay Conan in hand-to-hand combat. Clearly outmatched, Conan undermines Shan by questioning his motives for appearing on the battlefield, pointing out that if he really cared about the welfare of his worshippers, he would have freed them from the tyrant long ago. He only appeared now because he was in serious danger of losing their adulation. Conan's words make Shan's followers question their belief, which actually de-powers the deity. Conan finally disarms him and runs him through, forcing Shan to retreat to the realm of the gods, now deprived of the worship needed to sustain him.
 * Averted, and hard, by Crom. He's liable to kill anyone who dares pray to him, as it implies his gift of life and the will to do battle was not enough.
 * The universe of Asceltis (in french comic books Les brumes d'Asceltis and Les exilés d'Asceltis) embodies this trope. It is quite scary to see what Gods can do to keep people believing in them.
 * In the X-Men comics, the Dimension Lord Mojo's magic powers are tied to the number of people who pay him homage, which they do by watching his TV shows.
 * The Greek gods in The Red Seas are like this; on the Isle of Bronze, there are a group of massive statues originally built by Hephaestus in order to absorb faith and thus recharge the gods. For some reason, the Norse gods don't need faith in the same way. Satan also seems fine, but that's likely to be because most people do believe in him.
 * While it's likely not an issue for the true God, this is how The Demon came to reach his current level of power in Grimm Fairy Tales. In the beginning he was one of the weakest of all demons, but he was the first to realize that human prayers contained power, and it quickly took him From Nobody to Nightmare.
 * Harry Kipling (Deceased) works this way, with some creative upshots from Simon Spurrier. For example, since Klux was made from Kipling's tissue, Klux considers Kipling to be his creator and thus a god. Gaining a single worshipper means that Kipling is technically a god, and thus is able to kill other gods. Also, the New Atheist Militia realise they can destroy gods by massacring their followers, and their denial ultimately manifests as an anti-god which operates much like any other deity.

Fan Works

 * There's a Buffy the Vampire Slayer fic that deals with the gang visiting a realm that serves as a home for the forgotten gods to seek help from Ares. While there Ares comments that two of the gods don't really belong there since they seem to have plenty of followers, a South American god still worshiped by natives, and even more strangely, a Norse god who seems to have gained power in the last century.
 * Discussed and generally averted in Undocumented Features. Corwin, a recently ascended Physical God, seems to have no need for anyone to worship him, but that doesn't deter Chip, his self-proclaimed first worshiper, from doing so. Corwin's complaints of Stop Worshipping Me! have gotten to the point of gentle admonishment/Running Gag.
 * Averted in Drunkard's Walk -- the gods are twelve-dimensional beings who live in their own ecosystem and society, and don't seem to require anything from mortals, let alone prayer, but there are mentions of an undefined Covenant between gods and mortals which lays out benefits both sides get for agreeing to it.

Film

 * In Q – The Winged Serpent, the Aztec god Quetzalcoatl is prayed back into existence and begins terrorizing New York City in the form of a giant flying snake-bird thing with four legs. Incidentally, Quetzacoatl was one of the more benign Aztec Gods.
 * While God, angels and demons in Dogma apparently exist independantly of humans, they are still influenced by the way humans believe in them. This is made more explicit in some of the deleted scenes.
 * In Elf, Santa's sleigh is said to draw power from children's belief in him.
 * Played with in the remake of Clash of the Titans. Zeus and most of the Olympians sustain their immortality through the prayers of humans. This provides a problem when humans not only stop worshiping Olympus, but actively try and starve the gods of badly-needed prayers through blasphemy. As one would expect, it doesn't go well...
 * In Freddy vs. Jason, Freddy needs people to fear him to be able to infiltrate their dreams, so he became powerless when the inhabitants of Springwood systematically eradicated any trace of his existence. He uses Jason as a pawn to reinvigorate the locals' belief in him so he can return.

Literature
"Eros: "My mom and dad are Lust and Violence. This is L.A.""
 * The Dresden Files use this with a few unique ripples. Spiritual entities need some level of recognition to operate on Earth. Thus the various old gods (with a little 'g') have very little ability to act on their power. This is laid out in info concerning
 * Also evidence suggests that this doesn't apply God (with a big 'G') and His assorted Archangels.
 * In The Devil's Apocrypha, in which Satan Is Good and God Is Evil, God manipulated evolution on Earth to produce sentient humans in his image. He then advises us to commit brutal, violent acts in his name - the faith gives him nourishment. Satan and his followers, meanwhile, stand for free will and moral justice, and advise us not to mindlessly obey God and be reduced to his sheep.
 * Fritz Leiber's stories of Fafhrd and The Gray Mouser have a unique take: all temples in the city of Lankhmar are located along the Street of the Gods. Less-popular religions are located at the end of the street closest to the city gate; the more numerous a deity's followers, the farther from the gate his temple is located. Religions ebb and fall up and down the street throughout Lankhmar's history.
 * In the A.E. van Vogt story The Book of Ptath, gods are powered by "prayer sticks," which are actual machines (albeit, Sufficiently Advanced ones) that are physically manipulated by their worshipers to send power to the god.
 * American Gods uses this as a central plot point. There's some major Fridge Logic (or perhaps Fridge Brilliance) at one point given the slighting way one of them refers to Jesus. Given that deities are powered by belief, he (probably along with Vishnu) would likely be the most powerful god around at present.
 * There's also the implication that each nation has localised versions of gods: the American Kali mentions that there is a much more powerful Indian Kali, the protagonist briefly meets an Icelandic Odin and a powerless Jesus in Afghanistan is mentioned.
 * At first glance, the rules of the system could arguably have made Jesus so powerful in modern America that the conflict throughout the story would be beneath him. It's not his problem and neither side in the conflict would want him involved. On the other hand, note that gods in this setting don't actually need prayer itself, just belief. In that case, Jesus might not be all that powerful in modern America; see the premise of Small Gods below.
 * David Eddings uses it in the Elenium and Tamuli trilogies (the source of the page header quote). At one point, the goddess Aphrael becomes ill because her worshippers are being killed.
 * Douglas Adams' The Long Dark Tea-Time of the Soul: Old gods who have fallen out of belief become powerless destitutes, while a new god is actually spawned as a critical mass of Guilt builds up through the book.
 * In The Hitchhiker's Guide to the Galaxy, Oolon Colluphid says that the Babel Fish was used to prove the existence of God, but since God Needs Faith Badly, the concrete proof of his existence immediately caused his nonexistance.
 * Terry Pratchett uses this one a bunch throughout Discworld. The Discworld is lousy with small gods, most of them just "a pinch of existence," barely sentient and incapable of much more than disturbing dust or influencing the minds of animals. But the right minor miracle in the right place at the right time...
 * Small Gods concerns the rise, fall, and return of the Great God Om, patron deity of the theocratic empire of Omnia. He left at the height of his power, promising to return during the rise of the next prophet. When he does come back from his godly vacation, he finds himself inexplicably trapped in the body of a small tortoise, unable to conjure more than a spark of static. As it turns out, his followers began to believe less in him and more in his church, or more specifically that showing proper commitment to the church was less likely to have you tortured to death for heresy. By Om's return, only a single lowly acolyte believes in the actual deity Om rather than Omnianism.
 * The Last Hero introduces Nuggan, a minor deity hailing from Borogravia. An unpleasant god with an unpleasant mustache, he's a bossy little deity whose holy books are three-ring binders so he can constantly add to the list of Abominations that make life so miserable for his followers - when the Silver Horde brings a Borogravian bard to Dunmanifestan, they have to physically restrain the man from attacking his god. By Monstrous Regiment, the Abominations have helped cripple a war-torn Borogravia's economy (no more crop rotation) and have become so deranged (Abominating babies and the color blue) that citizens have taken to praying to the land's Duchess for succor..
 * In Hogfather, this fact is deliberately used in an attempt to kill the Disc's Crystal Dragon Santa by using Mind Control to stop children from believing in him. When the Hogfather falls out of existence, all that belief goes into completely random concepts that never existed before, such as the Verruca Gnome; the Eater of Socks; and Bilious, the Oh God of Hangovers. Oh, and it might mean the end of the world.
 * The Last Continent features the God of Evolution, who has no worshipers. He exists because he believes in himself very strongly, or more precisely, what he does.
 * During Going Postal Moist Von Lipwig perpetrated a con that resulted in the border-line small god Anoia, Goddess of Things Getting Stuck In Drawers, seeing a sudden surge in popularity and a possible promotion to Goddess of Lost Causes. Moist prays to her on the basis that she owes him, and Making Money reveals that this may have paid off -.
 * In hindsight, the golden Guardian at the Gate (a.k.a. "He looks just like my Uncle Osbert...") from Moving Pictures was probably a god of some sort, as he needs people's remembrance, and by extension, their belief that, if he's to.
 * This is the prominent plot point for Margaret Weis and Tracy Hickman in the The Rose Of The Prophet series.
 * The gods of the Dragonlance setting don't die without worship, but getting it does make them more powerful.
 * Mercedes Lackey can't make up her mind on this one. Most deities in the world of Valdemar are actually just aspects of the God and the Goddess (and the One is implied to be both at once), whose power descends down to the clerics instead of the other way around, but in one vignette it's explicitly mentioned that a demon can ascend to divinity by running a sex cult and feeding off all the worship (and a few worshippers too). This inconsistency came about because the short stories that demon appeared in weren't originally part of the Valdemar 'Verse, but rather were retconned in later.
 * Tamora Pierce's Trickster series mentions this principle, although it's not necessarily the number of people who believe, but who's in power. The trickster god Kyprioth needs his followers to defeat the mortal followers of his siblings Mithros and the Great Mother Goddess in order to gain enough power to defeat them, return from the exile they imposed, and resume rule over the Copper Isles.
 * There is also a case of regional variance in power. The Graveyard Hag is a fairly weak goddess of trickery in most of the world. In her domain of Carthak her power is so absolute only her father the god of death can oppose her.
 * A variation on this occurs in Tanith Lee's "Tales From the Flat Earth" series, where most of the god-like "Lords of Darkness" derive themselves from humanity's understanding of abstractions; i.e. they start out as mindless forces, and over time, as humanity personifies them, they become actual entities with full-blown personalities. The actual creators of the earth, however, the Gods, are pretty much oblivious to humanity, and ignore prayers and offerings. The Lords of Darkness are often worshiped as Gods, though (this is a major plot point in the second and fourth books), and are about one level or so below the actual Gods in power. Azhrarn, the first Lord, and personification of Wickedness, is different from the other lords, in that he's older than the universe, doesn't need human belief to be personified, and is probably as old as the Gods, but not as powerful; though it is implied that human perceptions of him do "fluff up" his definition, or at least has some relation to how he manifests, but only slightly. However, it is strongly implied, if not outright stated, that without humanity, Azhrarn would lose his sense of purpose, even though he would still exist. The other lords, like Chuz, Lord of Madness, or Uhlume, Lord of Death, are explicitly the products of human imagination, do not predate the universe, and it is implied that they would fade away without humanity.
 * The End of Mr. Y by Scarlett Thomas: Gods are created by belief and, of course, gain power from worship. Apollo Smintheus, the mouse god, has a cult of six guys in Illinois with a website. As you might guess, he's not particularly powerful.
 * In For Love of Evil, Piers Anthony shows that YHWH used to have a lot of power, but since belief in the Hebrew God had waned, his place had been usurped by the Christian God.
 * Subverted in The Soldier Son trilogy by Robin Hobb. The main character attempts to denounce that he owes ones of the "Old gods" a favour, saying that he "Believes in the Good God - You have no power over me" at which point the Old God laughs and tells him "How weak do you think Gods are? Do you think we require your belief in us to exist, how weak would such a god be?"
 * Star Trek: New Frontier brought us the Greek gods (who were also the Roman gods, the Norse gods, etc.,) known as The Beings, who were kin to Apollo in the original series episode "Who Mourns for Adonais?" They eventually get all powerful thanks to the worship of the Danteri... and the fear of the Excalibur and the Trident.
 * The short story anthology Gods of War (by Christopher Stasheff, et al) features this, but also indicates in addition to the Greek, Norse, and Japanese gods (among others) who fall into this trope, there is the 'one god' who is above the others and has no such concerns or limitations.
 * This is how it works in Dave Duncan's Great Game trilogy. The balance of power in that world is being upset by one demigod who has discovered a much more efficient means of getting divine power from worship - human sacrifice - and threatens to overthrow the major gods.
 * Played very straight in The Acts of Caine, but with a history. A long time ago, gods had whatever power they could draw from T'nalldion a.k.a. Home, the fundamental pattern/source of all magic on Overworld. Then this lowly human named Jereth got involved in a religious war, kicked some ass, earned the title of Godslaughterer, and died to establish the Covenant of Pirichanthe, which limits the power of all deities to what their believers provide. The exceptions are the Outer Powers which feed on the suffering and fear of sentients, and the Blind God, who is happily nigh-omnipotent on Earth despite the fact that his worshipers neither believe he exists nor care.
 * Partly how gods are created in The God Eaters, where a human born with magic is worshiped until (at least in the case of ) they gain enough power to return after death. Eventually, however, they amass enough power that they don't need belief to keep going. Still doesn't mean they're indestructible, though.
 * Several short stories by Lord Dunsany explore this trope, most literally Poseidon, in which the eponymous deity complains that he can no longer cause earthquakes without the blood of bulls. Perhaps humans just got smarter over the years.
 * In the Book of Swords, when people find out gods can be killed, their faith is shaken. Eventually, it is discovered that humans created gods by believing... which they stop, destroying all the gods. This leads to the question of "If humans made the gods, where did humans come from?" (Inversion of a question often asked theists in Real Life.)
 * Yahweh, in The Salvation War. An Lampshade is hung on it by an intelligence officer, who describes him as "Like the Ori."
 * Expanded by Dan Simmons in his short story Vanni Fucci is Alive and Well and Living in Hell, where different versions of Hell as well as God become true on the basis of the number of people who (consciously or not) believe in them. Vanni Fucci, one of the many people condemned to Dante's Hell simply because Dante did not like him very much, takes an opportunity to take over a televangelist's show and convince everyone not to believe in Dante's Hell anymore. Hilarity Ensues.
 * In Jennifer Fallon's Demon Child Trilogy, the Primal Gods are the ones that will exist as long as life exists (Love, War, the Oceans), and don't rely on human belief for power. They do gain strength through worship, but this doesn't entail praying (for example, "honouring Dacendaren" is a euphemism for stealing; Damin Wolfblade is favoured by Zegarnald, God of War, because he wins a lot of wars.) On the other hand, the Incidental Gods are demons that gather enough worshippers to become gods. The Big Bad of the series is an Incidental God that has gathered enough followers to challenge the Primal Gods' power.
 * In Harry Turtledove's Magitek novel The Case of the Toxic Spell Dump, this has become the province of bureaucracy; the EPA is responsible for creating artificial cults to sustain "endangered gods."
 * Maintaining artificial cults is as much a practical matter as it is idealistic; all of the magic is divine. One of the gods maintained by an artificial cult, for example, is Hermes, and spells calling on him are the basis for most of their telecommunications.
 * In this setting, it's especially clear that only worship will sustain a god: merely being acknowledged to exist doesn't suffice to keep them around. Thus, a pantheon of Chumash native deities can be dying out from lack of sincere prayers directed towards them, even though plenty of non-worshipers in the EPA are aware of their existence and concerned for their welfare as "endangered gods".
 * Averted in Percy Jackson and The Olympians, the Greek Gods continue at seeming full strength despite virtually no following in the modern world. The series in some ways seems to substitute this for the idea that the Gods are tied to Western Civilization, rather than any kind of worship, though they do draw power simply from people remembering they exist, regardless of worship. Its implied to tie in both to things like their symbols of power and the existence of Olympus itself.
 * If one goes by the Titans then worshiped is not needed at all. Despite being imprisoned for thousands of years none of the Titans try to work up cults or tie themselves into civilization. Power is based more on the factors mentioned and a few others.
 * This seems to be Zigzagged a bit, as Helios and Selene faded because the Romans apparently didn't worship them. It also happens with Pan because no one respects nature.
 * What seems to be is that the Gods survive as long as they have the will to survive, which they can lose when they are disrespected and unnecessary.
 * Averted in the The Kane Chronicles as well. The Egyptian gods have not been worshiped for thousands of years. Instead they exist in the Duet, or spirit world, and their power on Earth depends on a number of factors including what host they are using to manifest, time of year, and geographical location.
 * The Nameless Ones in Ursula K. Le Guin's The Tombs of Atuan
 * In Orson Scott Card's Enchantment, the old Slavic gods Mikola Mozhaiski and the Bear of Winter aren't killed by a lack of belief, but their concerns are much smaller and they try to live normal lives until they're needed again for godly duties.
 * Zeus is currently enjoying his retirement in the Caribbean.
 * In Simon R. Green's The Nightside Series, gods function rather like this. They even have harkers out on the Street of Gods trying to increase their base of worship to gain more power. Who often dissolve into shouting matches over who's dogma's right. It's a God eat God world out there...
 * Averted in the short story The Food of the Gods by Poul Anderson (in collaboration with his wife Karen.) Here it is stated that while worship - or at least reverence - is needed in order to achieve Godhood, once that state is reached the resultant deity is immortal, and no longer requires active worshippers. Some degree of continuing respect, however, is necessary if a God (or pantheon) is to have any continuing major influence on the mortal world. As an example, it's related by the god Hermes that when Christianity displaced Paganism, a dark age followed because the Olympians held too much of civilization within themselves. It was only when the Christian Trinity allowed Greco-Roman mythology to be rediscovered that the Renaissance became possible.
 * The Greek gods in Marie Phillips's Gods Behaving Badly have been holed up in a house in North London for a century or two, reduced to shadows of their former selves because the faith that made them powerful is now going to "the upstart carpenter" and his father.
 * C.S. Friedman's Coldfire Trilogy is set on a world where an occult force makes human imagination become real. Unsurprisingly, a number of god-beings start to appear who answer prayers in return for feeding on their worshippers' life-energy.
 * The zealot species Yuuzhan Vong of the Star Wars Expanded Universe seems to think this way: "The gods may have created us, but it is we who sustain them through worship."
 * Although with their creation myth (life was created through a terrible wound inflicted on its creator), this could instead refer to the expression of their worship through omnicide returning the gift of life to the gods.
 * A dark variant of this exists in the Malazan Book of the Fallen. Ascendant, mortals who transcended their limited existence to achieve a sort of demi-godhood, are generally weaker than gods who have secured large followings. Those gods gain strength, master the Warrens, and become even more powerful. Yet at the same time, accepting worship binds them to their followers, sometimes even distorting their nature and actions as the prayer imposes demands upon them.
 * In Laurell K. Hamilton's Merry Gentry series, the main characters are fairies, and referred to repeatedly as deities or former deities. Those who are still believed in [e.g., Frost] grow in power, and those who are no longer believed in diminish. There are also characters who exist as a sort of vampiric ghost of gods whose worshippers have died out, referred to as the Starving Ones -
 * The Fey are touchy about this, as most both believe in the existence of higher powers (which have no need for worship) and that they never were gods, seeing the collapse of most of their power (causing them to watch the deaths of the worshippers they could no longer care for) as punishment for the hubris of ever thinking they were. At the same time, they are influenced by human attitudes, and can feed off human notice, admiration and attraction. Also, by now the title character technically has a few human worshippers.
 * Warbreaker has an unusual take on the trope: the Returned subsist on what are effectively human souls (Breath) that must be given willingly. Thus, Returned need people to believe in them enough that they would willingly give up their souls to see them live another week.
 * Subverted in John Ringo's Special Circumstances series. The more people who worship a deity (even by proxy), the stronger their mortal servants are.
 * In the Iron Druid Chronicles the gods have their own sources of magic and don't really need to be constantly worshiped. However, the way people believe in them shapes their appearance and attitude. If two groups of believers in the same god diverge enough in their beliefs, the god will split into regional aspects.
 * There are dozens of versions of the Native American god Coyote
 * The American version of Thor is based primarily on the comic book character and is much nicer than the Norse version
 * Jesus does not like to appear to people because he would have to appear nailed to a cross and it's a very painful experience even for a deity. Mary's appearances are much more frequent and often triggered by the belief of old devout ladies.
 * In “Oblations at Alien Altars,” the introduction to Deathbird Stories, Harlan Ellison makes the point that for all their seeming puissance, gods are a remarkably fragile lot (although in one of the included stories he acknowledges that the truism is Nietzsche’s). He writes that “When belief in a god dies, the god dies.” Several of the stories address that idea.
 * Used subtly in Chronicles of Chaos:

Live-Action TV

 * Xena: Warrior Princess implies this, rather than it being outright stated. The Olympian Gods (the primary pantheon dealt with on the show), were shown to have a reach and influence as far as the middle east, and were considered the greatest of any gods in the show, while others were shown as powerful, but not nearly on the Olypmian scale. The show attributed it to less worship, and Ares even remarked to Kal once that his (Kal's) temple, and power had gone down hill since "those tributes stop[ed] coming in".
 * The initially conventional Christian-themed horror series Brimstone, in which a damned policeman is given a second chance at life by Satan in return for tracking down 113 souls who had escaped from Hell, undergoes a dizzying Genre Shift when Naturally, just as the series threatened to actually become interesting, the network pulled the plug.
 * The Merlin TV miniseries explicitly says that creatures like Mab and the Lady of the Lake only exist because people believe in them. Once Christianity moves in and people don't believe in magic, it doesn't exist any more. The climax has Mab literally fade into thin air because the crowd turn their backs on her and move on with their lives.
 * Stargate SG-1:
 * The Ori gain power from human worship, although they're still extremely powerful on their own. Once Adria takes their place in The Ark of Truth, SG-1 needs to take away her worshippers to make her vulnerable.
 * The Ascended Orici Adria, being the focus of everyone's worship as, is too strong for anyone to challenge. However, once she loses a significant bulk of that power, opening the way for an Oma Desala gambit.
 * In Valentine, it's said that it isn't so much prayer or belief that the gods need as it is "relevance." What this means for the main characters (Aphrodite, Eros, the Pythia, and Hercules, disguised as humans running an LA matchmaking service) is that if they don't do a better job at uniting soulmates, they'll cease being relevant to humanity, and will consequently lose their immortality.
 * Supernatural:
 * In one episode, the guys come across the haunting that wasn't - it was just a practical joke. The prankee buys it and posts the story on the internet where it becomes well known in a Urban Legend kind of way. Once enough people believe that there is a ghost there it actually appears. It was defeated by writing a weakness into the text - once enough people believed it, the ghost was defeated that way.
 * In the Christmas Special episode of season 3, the brothers run into two old Gods who are kidnapping people and sacrificing them to themselves. The couple boast that they use to be so powerful people would make sacrifices to them daily, but time moves on and they've assimilated themselves into modern culture and now only kidnap a couple people a year to sacrifice and keep themselves going.
 * In the episode "Fallen Idols", one such old god can only survive on the sacrifices of people that worship it. Since belief in the old gods has all but died in the modern era it transforms itself into whatever its intended victim happens to worship, like becoming Abraham Lincoln to eat a Civil War historian, appearing as Ghandi to Sam, and shapeshifting into Paris Hilton to devour a teenage girl.
 * The original Star Trek: The Original Series episode "Who Mourns for Adonis?" involves a cosmic entity claiming to be the Greek God Apollo, who says that his fellow gods faded away as humans stopped worshiping them. He tries to force the Enterprise crew to worship him, but their resistance to the idea ultimately convinces him that humanity has indeed outgrown him, and he chooses to fade away himself.
 * Heroes season 4 Big Bad Samuel Sullivan is a super whose geokinetic powers become stronger if he is surrounded by other supers who believe in him. In theory he could break the world if he had a large enough crowd of supers nearby. His brother Joseph hid the true nature of Samuel's power from him and deliberately limited the size of their super carnival to prevent Samuel from becoming too dangerous . Samuel is eventually defeated when Samuel is left all alone in an empty carnival as a powerless, broken, shell of a man.
 * Heroes season 4 Big Bad Samuel Sullivan is a super whose geokinetic powers become stronger if he is surrounded by other supers who believe in him. In theory he could break the world if he had a large enough crowd of supers nearby. His brother Joseph hid the true nature of Samuel's power from him and deliberately limited the size of their super carnival to prevent Samuel from becoming too dangerous . Samuel is eventually defeated when Samuel is left all alone in an empty carnival as a powerless, broken, shell of a man.

Oral Tradition, Folklore, Myths and Legends
"He calls on the heavens above and earth below to witness the judgment of his people. "Bring my faithful people to me— those who made a covenant with me by giving sacrifices.” Then let the heavens proclaim his justice, for God himself will be the judge. “O my people, listen as I speak. Here are my charges against you, O Israel: I am God, your God! I have no complaint about your sacrifices or the burnt offerings you constantly offer. But I do not need the bulls from your barns or the goats from your pens. For all the animals of the forest are mine, and I own the cattle on a thousand hills. I know every bird on the mountains, and all the animals of the field are mine. If I were hungry, I would not tell you, for all the world is mine and everything in it. Do I eat the meat of bulls? Do I drink the blood of goats? Make thankfulness your sacrifice to God, and keep the vows you made to the Most High.""
 * A Greek myth/folktale likely written in Christian times by Plutarch times tells of the death of the god Pan when people start thinking of him as only a made up story. One might wonder about the rise of Neo-Pagans, who have begun worshipping of Pan again. Have they resurrected him, or is their belief going unheard?
 * Subverted hard in the Judeo/Christian religions as seen in Psalm 50:


 * The Neopagan scholar Isaac Bonewits describes gods as functioning basically as the trope says. He's not alone; this theogony is quite common, especially among Wiccans and Asatru (Norse-pagan revivalists).
 * This trope is fairly common in real-world polytheisms, especially those with a substantial animist or pantheist component. Among modern religions, it is especially significant in the religions of the African diaspora in the New World (Vodoun, Santeria, Candomble, Umbanda), and in the Shinto animism of Japan. Historically it was an important though implicit idea in Hellenic- and Roman-era syncretism.
 * In a way, there's a "Person Needs Prayer Badly" in medieval European Catholicism... in order to go to Heaven (or reduced their time in purgatory) and join the Angels, the soul of the deceased needed to be prayed for. This led to the modern idea of the funeral, as well as other ideas.
 * It is still part of the Catholic beliefs, but you only pray for the soul in Purgatory as man has no role in deciding the salvation of souls.
 * While this trope is believed by few in real life concerning actual deities, there is no denying that a religion's influence and power increase with the number of followers.
 * It would be interesting to know the source for this assumption, that only few do, as above mentioned examples of people who do believe so, seem to indicate a reasonable high number.
 * That is assuming that the above examples are correct and not based on faulty scholarship or plain misunderstanding. For example, as a Heathen (which includes Asatru) of 11 years I can say for a fact that this belief is not common among Asatruar even though an above troper says it is.
 * It could be that the claim was based on how religious beliefs affect politics, economics, etc. Like the persecution that followed with the change of reigns between Protestant and Catholic, the Puritans in the USA, Judaism and other religions in the Middle East, Russia/USSR, etc.
 * Maltheists (those who believe in God, but believe that God Is Evil) often believe that God will die if nobody worships him. Which is what they hope will eventually happen, because they believe humanity cannot truly be free until God dies.
 * The state religion of the Aztec or Mexica Empire believed the gods are always hungry—not for belief or prayer, but for human and animal sacrificial victims—and that if they were not fed a steady diet of the hearts of brave warriors, they would surely destroy the world, as they had many times before. The whole Aztec political system was designed to prevent this by waging enough wars that there would always be plenty of POWs to sacrifice; in some cases, Tenochtitlan and another city-state would stage a set-piece "Flower War" with no objective but giving each side a chance to capture some of other's soldiers for sacrifice. (Not every state the Mexica forced to participate in this seems to have shared their level or form of piety on the matter—a circumstance Cortez, when he arrived, found very useful to his purposes.)
 * To put it more bluntly, many of the Aztecs' neighbors, and particularly the less pious ones, saw them as a mixture of The Empire and The Religion of Evil, seeing as the Aztecs had a habit of capturing whole villages for sacrifice and then moving into the vacated homes.

Tabletop Games

 * Dungeons & Dragons:
 * In the Forgotten Realms, a god's power is determined by his/her number of worshippers, and needs at least one worshipper to maintain Divine status (albeit at a demigod level). The only exception is the overdeity Ao, who needs no worshippers to maintain power because he rules over all of the universe. This is a relatively recent development, as the deities were independently powerful before the Avatar Crisis, when Ao got fed up with nobody doing their duties or taking care of their worshippers any more.
 * Ao actually punishes anyone who tries to worship him by inflicting them with bad luck until they stop.
 * The post-Avatar Crisis fluff tended to suggest, when the subject came up, that the Gods did gain power from being prayed to and having followers before the Crisis. What Ao did after the Crisis was, essentially, toning down the power you gained from your Portfolio, and ramping up how much power you gained from belief.
 * In the Planescape setting, this mechanic is explained via the fact that the Outer Planes (where the gods live) is shaped entirely by belief.
 * In basic D&D, the Immortals need at least some worshipers or they fade away. They can come back if someone starts worshiping them again for some reason. A new Immortal can survive on power from his sponsor for his first year or so, but he'd better have found some worshipers by then.
 * Averted in Dragonlance, where the deities do not need any worshipers to maintain their power. They do need mortal followers to have much influence in the mortal world however, but they will not die from a lack of followers.
 * Baldur's Gate being mostly canon to mainstream D&D shows us that a dead god can still excist if it's followers are still undead echoes, believing they must live for eternity guarding the temple of a dead god, which at the same time creates a demon of hatred to fight their dead God, time and time again in an endless cycle, akin to Ragnarok. The God wouldn't be without it's Guardians, and the Guardians wouldn't be without their God, thus both perpetually creating a Living Echo of each other.
 * In Demon: The Fallen demons need faith to fuel their powers. They can either force steal it, which causes spiritual damage, or set up cults of various stripes to get a small but steady flow without necessarily hurting their worshippers (unless they want to be hurt).
 * The New World of Darkness:
 * This setting has the Astral Realms, which include the Temenos, the collective consciousness of humanity. Among the conceptual archetypes present there are every god ever worshipped. In this case, since they are formed through human belief, their power is proportional to how much humans regard them, not necessarily through worship. For example, Anubis exists in the Temenos, and though not as powerful as he was when he was actively worshipped by a powerful nation, he is still a relevant and well known symbol, which means he still possesses the power of a minor god. Other gods are less fortunate. Since the Temenos is a focal point for all human knowledge and experience, even a completely forgotten god would still exist somewhere, albeit significantly weakened. Its also suggested that some Temenos gods might be based by humanity on truly divine beings (a theory particularly popular with devout mages who suffer crises of faith upon learning they can meet their deities in the Temenos).
 * Similarly, various spirits in the Shadow realm are often shaped and empowered by human belief. Whether a particular one appearing as a god was an inspiration for human worship or was formed by human worship is often unclear.
 * The Chaos Gods in Warhammer Fantasy Battle and Warhammer 40,000 are both formed and fuelled by the concepts they represent. On the other hand, they don't really need prayer: every feeling of anger, ecstasy, hope, or despair feeds one of the Chaos Gods, whether the person who has the feeling is a follower of Chaos or not. Background material indicates this is the same for all deities, except for the God of Atheism, who gets strong if people don't believe in anything.
 * It is speculated that the Emperor of Mankind's almost militant atheism and denial of any superstitious talk of "daemons" was a direct attempt to starve the Chaos Gods of belief. While this effort obviously failed, the Imperium's faith in the God-Emperor of Mankind may have helped him become a proper deity himself, enhancing his already-formidable psychic presence and giving humanity a fighting chance.
 * Exalted: not only do Gods little and big benefit from worship as the currency of Yu Shan, but anyone can earn Essence if they get a Cult worshipping them. Something many player characters will find handy.
 * Or the opposite, depending on the campaign: if you start the game marked for death by beings whose job is strongarming gods (which is normal), having a higher profile and more ways to be attacked make it a mixed blessing at best.
 * In Rifts, Gods are naturally more powerful in their own home dimensions, and ones where they have a strong base of the devoted, than in any other dimension.
 * Before coming up with Magic the Gathering and acquiring TSR, Wizards of the Coast released a supplement called The Primal Order to provide formal system-independent rules for deities and ways they interacted with mortals and each other. As described, all gods had a certain amount of power at all times (unless deprived of that by suitable attacks, at which point they could expect to shortly cease to exist barring possession of a loyal home plane to regenerate from over the course of a century), but gathering worshippers both living and dead as well as acquiring planar real estate and spheres of influence all provided significant boosts that only the strangest gods would want to do without.
 * This is the status for the gods in the Scarred Lands campaign... except for Chaotic Evil Vangal, who derives his power from how many people his worshippers slaughter. Otherwise, he would've died, since most people aren't too keen on worshipping a Blood Knight who doesn't even pretend to have any other motive besides fun.
 * In Scion, a character's Legend rating represents how well-renowned an individual is, and determines the strength of his divine powers. Full-blooded deities have very high Legend ratings, but some very famous mortals even without divine Ichor can have very low Legend ratings.
 * The godlike Reckoners/Manitou of Deadlands gain more power when they spread fear and belief in the supernatural.
 * The non-Abrahamic gods in In Nomine are called Ethereals, explained as being formed by humanity's imagination and empowered by their worship. Yves came up with the different Abrahamic religions in order to undercut their power, and Uriel opted to wipe them out directly before God yanked him up to the Higher Heavens to have a little chat with him about it. Of course, the Ethereals say that Yahweh/Jehovah/God was one of them and simply managed to gain enough worship to Retcon reality.
 * Eon, the highly detailed Swedish RPG, kinda works like this; gods generally don't die, but lack of worshippers can lead them to the brink of "starvation". An entity called "King Frost"; an amnesiac old man walking the frozen deserts of the northlands, is theorised to be a 'fallen god' clinging to life. It's worth to note that the gods can return when they get worshipped again though.
 * Over the Edge, here it's part of All Myths Are True, one character in a splatbook takes a drug that allows humans to commune with the gods.

Theatre

 * This one is Older Than Feudalism - in The Birds, the Greek gods lose power because the prayers they were offered couldn't reach them because of a great wall built in the sky. (Actually, it was not prayers that were intercepted - it was rather more physical smoke of animal sacrifices.) The gods did not immediately lose power - rather, they suffered from hunger, although they turned out to have some stockpiles of smoke and rationed the smoke. It was a plot point that not only Greek gods suffered - non-Greek gods were also starving and did not have stockpiled smoke. They accordingly threatened to attack Greek gods unless they made terms with Nephelokokkygia that would lift the blockade.

Toys

 * Physical God Mata Nui of Bionicle fame would have died if the Matoran people had stopped doing their jobs. And this trope was applied with good reason—he was a Humongous Mecha, and the Matoran kept him functional by doing essential work inside him.

Video Games

 * This ends up becoming a gameplay mechanic and a key plot point in Hyperdimension Neptunia. Goddess party members gain stat points when the shares of their homelands increases, usually by completing dungeons there.
 * Alundra: The villagers of Inoa pray to Melzas, who is (unknown to said villagers) actually evil. Also Nirude, a giant god, lives off the prayer of midgets.
 * The Elder Scrolls: The more people worship a given deity, demigod, or what-have-you, the more powerful they become. Greater gods like the Nine Divines and Daedra Princes can survive without it, but will be seriously weakened until they get more followers. Lesser gods can be outright killed by lack of worship. The reason it's easier for greater gods is because they personify widely-known abstracts, so even if all their followers in one culture are purged, they have another culture to pick up the slack.
 * Some EU and even in game dialogue hints/explicitly states that after the events of Morrowind the leader of the indigenous Tribunal religion, Vivec, disappears without a trace. And the large floating rock used as a religious prison and held aloft by "the love of the people for [Vivec]" smashes into Vvardenfel, causing massive destruction across the entire island. Did you forget that you're the one who revealed his religion as a sham?
 * Becomes a plot point in Skyrim, where the Thalmor, a faction of elven supremacists, have forced the empire to ban the worship of Talos, leading to the Stormcloak rebellion. The stated reason for this is that the Thalmor refuse to accept that a human could achieve godhood, although it is suggested that
 * Prayer is the source of Mana in Black and White, and determines the size of your territory.
 * Power-ups in Okami come from the praise you get for performing miracles. Overall, this trope seems to be one of the game's underlying themes, as it's mentioned quite early on how people's faith in the divine has dwindled.
 * This mechanic returns in the sequel, Okamiden.
 * In Age of Mythology, the player literally generates favour for their gods to produce miracles. Greeks pray at temples, Egyptians build monuments, Norse go to war, and Altanteans control town centers to generate favour.
 * Seven Kingdoms had temples where you'd sent people to pray to your nations "Greater Being" (based on a god of the respective mythology). In this case, you'd could either summon the god himself (some are fighters, some have special abilities) or trigger a random miracle.
 * Used for evil by Breath of Fire II,
 * Subverted by Ladon the dragon god, who's a bit grumpy that nobody believes in him anymore but nonetheless continues to exist.
 * The more worshippers you have in Populous, the more powerful miracles you can perform.
 * In the first two games, only settled worshippers benefit you in that way, by the strength of the settlement. Giving you the choice between producing a lot of worshippers or personal power and tougher worshippers.
 * This concept formed the premise of the 10th Touhou game, Mountain of Faith - goddess Kanako Yasaka, faced with fading away due to modern Japan's waning faith in the divine, decides to relocate the Moriya Shrine to Gensokyo, where she ought to have an easier time finding worshipers. Unfortunately this muscles in on the local religious "authority," protagonist Reimu Hakurei, and Danmaku ensues.
 * Once the tea parties are over, the Moriya Shrine becomes an established fixture in Gensokyo, surviving quite comfortably on the faith of the local kappa and tengu. That said, Kanako hasn't stopped in her efforts to increase faith, and has repeatedly attempted to introduce modern technology into Gensokyo as a sort of "fire from the gods" ploy. This has met with mixed success - her plan to build a fusion plant sparked the events of Subterranean Animism, in which a ditzy hell-raven went mad with the power of a sun god and tried to turn the surface world into a new Hell.
 * Fan works involving the Moriya Shrine's miko, Sanae Kochiya, often have her working to gather followers or otherwise ensure that her goddesses don't fade away.
 * Lampshaded in Blood Omen: Legacy of Kain when Kain remarks, "The act had taken on the feel of ritual. Isn't it strange how we must bribe our gods to stay?"
 * In Fate Stay Night, the Heroic Spirits (not outright gods but at least a few levels of spiritualism above humans) mostly exist due to - and are partially sustained and empowered by - the belief they've inspired in humanity. Their strength appears based partly on their actual power and partly on pure Popularity Power. As Rin explains in the game prologue, even fictional characters count, what matters is the image created by the minds of the people. The game features two major explorations of this -, who is entirely fictional in the Nasuverse. In other words, the pure belief that humanity has in the existence of said hero is so strong that it allows him to exist, . On the flip side, ; nobody knows of his existence and he therefore owes neither his existence nor any of his powers from belief, persisting as a Heroic Spirit only through the connection all Heroic Spirits have with the earth itself. Heracles, naturally, gets top billing either way you look at it.
 * ActRaiser:
 * Subverted in the original Actraiser for the SNES. While you gain levels as your population grows, it turns out that your powers are dependent on the number of people on the planet, not their faith. At one point, a Path of Inspiration turns a lot of people in one country against you, but it doesn't lower your levels. Additionally in the end, but you don't fade away or anything.
 * In Actraiser 2, one of the towns you need to save is initially closed off, because the townspeople there don't believe in you (and thus you can't read their minds).
 * During one Sidequest in Baldur's Gate 2, you meet an avatar of a god with so little belief that he is fading away. and a small village of followers were bound to immortally guard "the device" forever, over the years their faith has transformed to hatred and the avatar can barely even show himself, much less do anything.
 * In Illwinter's Dominions II the faith of people in various provinces is represented by a candle. This affects the knowledge you have on the province, the level at which you can affect it and, should you move it into the area, the hitpoints of your Pretender God.
 * The old gods reveal to the player in Ultima VIII; they are nearly powerless now that about everyone worships the four new gods instead.
 * Paper Mario. The star spirits in the first game gain power from the wishes of the denizens of Mushroom Kingdom. In the final boss fight, the young star spirit Twink gains enough power from Peach's wishes to beat up Bowser's sidekick and help Mario save the day.
 * Sierra's City Building Series cuts both ways. While gods need sacrifices or festivals almost constantly, ignoring them only makes them angry. Cue earthquakes, plagues, floods, failing crops... On the other hand, keeping them happy also brings benefices.
 * In Shin Megami Tensei, the gods, demons, and spirits feed on a substance called Magnetite or Magatsuhi - which is human belief and emotion and works as the setting's mana source. In Nocturne, when humanity was wiped out, demons had to abuse Artificial Humans to produce Magatsuhi to stay alive.
 * For as long as a single person believes in YHVH as his or her god, He will return, again and again. Unfortunately, it seems the Mega Ten universe works on the same principle as the Malazan example above-Humanity's own inner darkness and desire for a God that accurately represents them has horrifically twisted Him into a bitter, unsympathetic tyrant with nothing but contempt for humans.
 * Even worse, this trope may have been the origin point for Nyarlathotep, a monster born of the hatred, fear, greed and despair of all of mankind. As the Shadow of Humanity's collective unconscious, it is really easy to see where the title of "Crawling Chaos" comes from.
 * Referred to in Sam and Max Freelance Police, where Hell is conquered because too many goofy portrayals in media mean that nobody believes Beelzebub to be a threat any more and thus he is weakened, whereas the Soda Poppers are widely hated enough to have the power to challenge him.
 * The Neverwinter Nights 2 Expansion Pack Mask of the Betrayer is set in the Forgotten Realms. It shows just how far gods dependent on worship will go. They built the Wall of the Faithless, which punishes not sinners but non-believers. Being a atheist or a paying lip service to religion is the biggest of all sins against all the gods, and thus the good, evil, lawful, and chaotic gods all agreed that atheists shall be punished by ultimate torture and eventually the very destruction of their souls by having your soul slowly digested over thousands of years.
 * It should be noted that if you read the supplements, you'll find out that the current administrator only makes use of the Wall because the other gods forced him to. Also, this is a setting where the gods are very real and walked the earth in mortal form en masse less than twenty years ago (a period known as the Time of Troubles). On Toril, literally every atheist is a Flat Earth Atheist: ending up in the Wall for atheism is akin to starving to death because you don't believe food exists.
 * WARNING! PLOT POINT AHEAD!
 * This is a plot point in Disgaea 4: A Promise Unforgotten. The Netherworld and Celestia need fear and love from humans to maintain their power, but it's become difficult for demons to plant fear in humans since humans have become so corrupt that they now fear themselves more than demons. As a result, this means they no longer have to pray to angels for protection and guidance.
 * BlazBlue has an interesting variation on this trope: Hazama/Yuuki Terumi's existence is sustained by other people hating him. Which really does explain his thorough traumatization of Ragna at the start of the story, as well as his behavior in general... Of course, he also has his network of Observers and Life-Links to fall back on if that lifeline ever failed him.
 * It should be noted that though hatred sustains Hazama/Terumi's existence, thus making it necessary for him to be the worst kind of Jerkass possible in order to stay alive, he is still as far from sympathetic as one can get. He has no shades of I Did What I Had to Do, and has even openly admitted that he loves ruining other people's lives for the sheer hell of it.

Web Comics

 * In A Moment of Peace the gods of the universe eat human emotions to survive, like baked cheer or gruel made of sorrow.
 * Played With to an epic extent in the (now completed) Indefensible Positions. It took this to its logical extreme by having EVERY Me Me being a god powered by people's thinking about them.
 * Fans has the occasional god make an appearance. These gods usually claim they were conceived by Roman clergy, during nights with a little too much wine. These gods include the god of gaming, and the anti-cupid (who shoots you with a tommy-gun and takes away your devotion to another person).
 * The creators of Exterminatus Now have mentioned that this is how things work for the Gods in that world, though it is never explicitly stated in the comic.
 * The Order of the Stick universe in general employs this trope to explain any god not in the four three original pantheons. In particular, Elan and some orcs are Banjoists, worshippers of Banjo the Clown, god of puppets. He doesn't have many followers, so his divine lightning is little more than a spark. One of the prequel books reveals that mortal character can ascend to godhood in this manner.
 * Since Elan was unwilling to leave Banjo (who is an actual puppet) with the orcs, he creates Banjo's twin brother and rival, Giggles the Clown, as the god of slapstick. The violence-loving orcs appreciate this, and immediately convert. So Banjo went back down to a single worshipper, but since they were defined as equally powerful rivals, that probably remains the case. The OotS-verse has established that being defined as a rival gives free XP to keep one side from being too weak for the role.
 * Elan once tried to get Banjo inducted into the Northern Pantheon, specifically to gain more worshippers. The local priest angrily rejected this idea, and Elan then decided Banjo was too good for their pantheon, unaware that Odin (who likes puppets) approved of the idea.
 * Similarly, several elves and one goblin became so revered after their deaths that they ascended to godhood
 * The Gods of Arr-Kelaan gain power from their followers, but mostly they provide their own power.
 * Interestingly, the Abrahamic god is shown to be a concept created by a pantheon of minor gods in order to conserve the lessening magic in our world.
 * In Parallel Dementia, most nightmares (read: supernatural beings) gain power from belief. This also works for human, as demonstrated by a legendary assasin who faked her death who still gains power from people believing in her former name, Mistress of Blades.

Web Original

 * Seen in the Whateley Universe with the New Olympians. After escaping imprisonment (by whom hasn't yet been revealed) into the modern world, the old gods of Olympus find themselves greatly weakened and without worshippers to draw power from, and end up having to take mortal hosts. Who in the present day form their own loose school clique at Whateley Academy...
 * It's also been mentioned in the canon background material that even simple spirits (basically considered randomly occurring self-motivated 'knots' of magical energy) may be able to evolve into 'gods' over time if given a source of worship to draw on.
 * Used in Adylheim: the less powerful gods require constant supplication and sacrifices to be made in their honour, whereas the more powerful ones merely use this as something of a divine power up. In return they're usually inclined to offer everything from providence to small miracles.
 * Because of a Screw Destiny maneuver by The Chosen One in the Metamor City setting, the old gods of the pantheon are now physical gods and have lost most of their strength and power. They gain gain some of their power back by way of worship from mortal souls.
 * In the original Metamor Keep setting, where the gods are at the height of their power, they draw power from faith and actions done in their name. Though aside from the priesthood most worshipers only pray when they need something, and such favors often have a significantly higher cost.

Western Animation

 * While negotiating a system of catacombs as part of a ritual ordeal in Thundercats, Lion-O discovers a beautiful, brightly-lit room full of treasures. A mysterious figure, clearly terrorized by his presence, attacks him but is too weak and decrepit to put up any resistance. After Lion-O assures him that he is not a thief, the creature introduces himself, explaining that millennia ago he was a much-renowned god, but that his power has withered to virtually nothing after enduring many centuries without having been worshipped. He goes on to explain that anyone can become a god, but few attempt it as without worshippers this is certain doom.
 * In the Care Bears episode "Share Bear Shines!", Princess Starglo explains that stars are powered by belief and wishes, but so few people believe in her or wishing on stars that she doesn't have much power left, which leads to her turning off all the stars in the sky (including the sun). By the end of the movie, she nearly fades away, but is saved by a burst of belief from the Care Bears. (One would imagine that seeing all the stars go out would be a powerful reason to believe, but there you go.)