Lowest Cosmic Denominator

The basis for the series is that our heroes, representing the forces of Good, are engaged in a constant battle with the forces of Evil. But, since folks are touchy about religion, all the names have been changed to protect propriety.

This also gives us leeway to create cool, modern (or post-modern) sounding names for our Hero. "Slayer" is much easier to sell to the general public than "Templar", and certainly better connotatively than "Inquisitor". "Whitelighters" might be "Angels" or "Saints", but might not. They are much more new-agey, and handy around the house, too. Samantha Stevens nose-twitched away most of the stigma against Witches, so we can go with that, but what say we call the ruler of the Netherworld, our biggest Big Bad "Prime Evil" so as not to offend any Theistic Satanists. And let's avoid any problems in the Bible Belt by just calling the ultimate good guys the "Powers That Be" rather than naming any "real" gods or angels. This also helps if you want one (or two or three) of the Powers That Be to go Evil.

Of course, this also makes it easier for us to make sure that Our Vampires Are Different, maintain the Balance Between Good and Evil, and come up with a fresh Sorting Algorithm of Evil. Theology majors and occultists won't be able to complain that we didn't do our homework, because we eliminated all that dry scholarly crap in the interest of making our background accessible to the average viewer.

It's The Theme Park Version of religion, where everybody's not using the "G" word. Related is Witch Species.

Literature

 * In His Dark Materials, one of the most famed examples: God is 'The Authority', the church is 'Magisterium', Inquisition-for-children is 'Gobblers', and so on.
 * Played With in Lord of the Rings. Archangels are "Valar", demons are "Balrogs", and God is also called "Ilúvatar" (approximately similar to "all-father" in Sanskrit, which is also the word for Jupiter in Latin.) But Tolkien avoided showing anyone practicing religion save for the Numenoreans, who were extremely ecumenical in their beliefs. According to Tolkien's Catholic theology, all of the characters were "virtuous pagans" and as such anyone they worshiped could potentially count as "actually being" angels or demons according to the tenets of Catholic syncretism.
 * This is clarified in The Book Of Lost Tales, in which a pagan Englishman's own Germanic gods are identified with the Valar, and the Elves also call them 'the Gods' - but when the Englishman then asks if this Ilúvatar is of the Gods, an Elf replies 'Nay, for he made them'.
 * In the Old Kingdom trilogy, Garth Nix uses 'Charter Magic' and 'The Charter' to refer to the orderly, set and harmonious schemata of magic that keeps the universe running, while 'Free Magic' refers to the corroding and chaotic magic that The Charter was created from and which is inimical to the natural order of the universe. Worship of the Charter, and the "Seven Bright Shiners" who created it, seems to be the religion in the Old Kingdom, though the most we see of this is in baptisms upon a child's birth.
 * While the actual religious practices are not elaborated on in detail, the
 * Meljean Brook's The Guardians series - the Guardians are pretty much all angels that were born human, they just don't use the a-word.
 * In Isaac Asimov's The Last Trump, God is referred as "The Chief", and in other Asimov's short story called "Gimmicks Three", the demons refer to divine orders as "orders from above".
 * Stationery Voyagers goes about this trope half-heartedly. It keeps its doctrines scholarly without regard for controversy; but changes names around as much as it feels it needs to. Jesus is "Minshus," which allows him to have the same background as Jesus, but a name that sounds more like "Confucius" without having to agree with Confucius. "Father Son and Spirit" become "Primalus, Secondarium, and Trimalus." Gabriel is renamed Gabon, Michael becomes Martarel, and the Serpent is replaced with a Chameleon. The Tree of Knowledge is replaced with the Lakeith Pit, which combines the Tree's symbolism visually with Pandora's Box. The Drisalian War Outcome replaces the Tower of Babel, and the Drisalian Curse replaces the Confusing of Tongues. It's all used 1) to justify humanoid stationery running about and 2) to justify Our Angels Are Different.
 * Parodied in the Thursday Next books with the invention of the GSD Church - Global Standard Deity. Essentially a mishmash of all world religions, in which pretty much anybody can believe anything they want about it.
 * Even further parodied as the books go on; Joffy's stories about his work make it clear that the Church of the GSD splits into thousands of bickering factions soon after it is created, essentially reverting religion back to the way it was before.
 * In the Young Wizards series, God is called the One, His angels are called the Powers That Be, and the devil is called the Lone Power (because it is separate from its fellow angels).
 * On the other hand, it's made pretty obvious that the Lone Power is Satan (without ever explicitly saying so), a few line explicitly compare the Powers to Abrahamic angels, and the Power whose duties/role closely match that of the archangel Michael is referred to as "Mike" by the Lone Power.
 * These facts are explicitly stated within the series. The Lone Power refers to himself as "the star of the morning" (ie: the morning-star, Lucifer) in one book, Nina goes to a church to pray to the One in another, and the Archangel Michael (who was also, apparently, Athena and Thor) shows up in one of the endings.
 * The Powers correspond to the gods of every religion (although some are closer to the mark than others). For example, in The Book of Night With Moon series, the main Egyptian gods are stated to be close cognates of the feline aspects of the Powers. (In the same book, a wizardly cat is bemused and disturbed at how badly an unnamed human religion - which is clearly some branch of Christianity - misinterprets the nature of the Powers, in particular the idea that the One requires affirmation of Its existence or the sort of extreme and self-effusive praise that would make a person who thinks anything like a sane mortal incredibly uncomfortable, and that insufficiently good people will be sent to Hell after their deaths.) They're not just Christian angels and the Christian God with the serial numbers rubbed off, although they would fit pretty well into some liberal, non-traditional interpretations of Christianity.
 * A special introduction in the new edition of So You Want to be a Wizard states that, at the very least, the idea of the Book of Night with Moon itself, the definitive text of everything in existence, came from the author chancing upon a bit of Midrash. Everything else apparently flowed from that Book and from the title So You Want to be a Wizard as the author built a world to support her story idea.

Video Games

 * In Mother 3, God is referred to as "Guy in the Sky" when Lucky leaves club Titiboo, although, this being a Mother game, it could very well be referring to the player instead. Either way, euphemism is used.

Comic Books

 * In The DCU, it's established that -most- pantheons are pretty much one and the same. Sentient entities play similar roles throughout in some cases. So the creators are free to go with some made up Religion or right into Catholicism. Both happen a lot. Similarly, Hell is full of classic mythology and made up characters. Power struggles happen constantly, with various demonic horrors fighting/displacing/killing mythological beings or made up characters. To cap it off, DC comics even had Hell overrunning Heaven. Heaven got better.
 * And then there's Vertigo. Among other things, . It's probably best to just not talk about that though.
 * In The Marvel Universe, direct mentions of Judeo-Christian entities such as Satan were not uncommon (The "Son of Satan" even had his own series) but in the 80's it was stated (in the Handbook of the Marvel Universe) that NO such character had ever appeared in a Marvel comic; even Son Of Satan's father was retconned into being another demon. This has loosened in recent years.
 * The Fantastic Four met the One-Above-All (in other words, God) in one adventure. It took the form of Jack Kirby.
 * The Avengers managed to have multiple members with faith-based powers, including one Catholic among pagan demigods, and still kept religion out of the comic's theme. Lampshaded once, when they all took religious sabbaticals at once leaving the team short-handed, Hawkeye complained "This is the Avengers, not the God Squad!"

Live Action TV

 * Buffy the Vampire Slayer only mentions that Willow is Jewish in passing, and pretty much glosses over religion entirely after that. The bad guys are evil, many are in fact demons (or gods, in the case of Glory), but none of them cite references from the Bible or Qur'an on their resumes. (A few early examples do come from existing Christian tradition, though.) At one point, Buffy dies and goes to heaven; there are various points of view as to what the theological implications of this are for her and the series.
 * However, crosses and holy water and the Bible do damage vampires.
 * Wicca is treated as a source of power rather than a religion. In fact, only one group treated Wicca like the real, modern day religion, and that was Willow's college coven. They were portrayed as naive fools. It had already been (rather arbitrarily) established that in the Buffyverse, humans developed witchcraft from copying the older demonic races. There the real Wiccan religion would be somewhat out of place and out of touch with its origins.
 * Actually, that group was more fluffy bunny that actual Wicca, but still closer than the Buffy version.
 * If one were to class vampires as demons (technically correct, by the show's mythology), then many of them claim to have been present at the Crucifixion. Lampshaded by Spike, who pointed out that if every vampire who claimed to be at the Crucifixion actually was, there'd be no room for the crosses.
 * Charmed also creates a fictionalized mythology from whole cloth, with Witches being born to the power, Warlocks wanting to usurp the power, Demons led by the Source, Whitelighters following the orders of the Elders, etc. They do address Christianity early on, with Piper worrying that she is "evil" because she's a witch. Her worries are relieved when she enters a church without bursting into flame.
 * Averted thoroughly in the Stargate Verse: the characters certainly do their mythological homework, and gods and godlings from virtually every pantheon, including Judeo-Christian-Islam, are either name-checked or attributed to Sufficiently Advanced Aliens.
 * One episode in Sokar's season in the spotlight (4th?) had him posing as Satan to control some primitive screwheads he'd grabbed from Medieval Europe. They were very careful to have Teal'c claim he didn't think a Goa'uld would ever act like capital-G God, though.
 * Averted in Season 4 of Supernatural. Throughout the series, there had been demons (usually using the names of Biblical demons), but no sign of any angels or any reference to God. Then, suddenly, there's not only Castiel, but the fact that he tells Dean that God himself commanded he be . Sure, some of the mythology is changed (66 seals must be broken for ), but the show doesn't shy away from using real world religion.
 * Obvious aversions: Shows like Reaper or Joan of Arcadia, which explicitly feature Satan or God (respectively) as major characters and speak openly about Christian lore.
 * The Fallen mini-series features angels, Nephilim, Hell, and The Devil, but God is always referred to as "the Creator".
 * As late as the mid-1970s, prime-time situation comedies didn't have characters mention God, apparently because the nature of comedy is to be less than reverent. In the Happy Days episode where Fonzie seeks out baptism, the priest never utters the word "God", instead pointing skyward and speaking piously of "Him".

Newspaper Comics

 * Dilbert was originally to feature Satan, but due to Executive Meddling it wound up with "Phil, the Prince of Insufficient Light," who sometimes darns people to Heck. (The writer has admitted this is funnier than what he originally planned.) On the other hand, God and angels have occasionally been referred to in more proper terms.
 * It isn't entirely clear if Phil is even supernatural. It was eventually revealed that he is the boss's brother.

Role Playing Games

 * The first edition of Advanced Dungeons and Dragons used various polytheistic religions (some from the real world, some made up for the setting) so as not to stomp on any modern religious toes. This ended up backfiring on them, as various groups of Moral Guardians claimed that lack of the Christian God was "proof" of the game's "satanic" nature. (Notably, the game still does use polytheistic religions, since they've become so incorporated into the flavor of the various settings. In particular, the Nordic god Tyr and the Egyptian god Horus appear in the pantheon of the Forgotten Realms setting.)
 * Devils and Demons (different competing factions of fiends, one tyrannical, one...let us say "free-spirited") were turned into "Baatezu" and "Tanar'ri" for the 2nd edition to appease concerns that Dungeons and Dragons was satanic (even though these were presented as opponents you killed). When 3E came around, the taboo lessened and the Tanar'ri and Baatezu were made into types of demon and devil (albeit the most prominent ones). Lore went on to state that non-Tanar'ri and Baatezu were mostly exterminated by the Tanar'ri and Baatezu.
 * Interestingly it's completely possible to run a D&D game where the one true faith is Christianity. There are already rules for getting Divine spells from infernal masters, so it's just a matter of taste whether you want to have a pantheon or one true God (possibly including Jesus) and many demonic pretenders or even many good deities serving an Overdeity that is the true god. The latter option is the one taken in The Silmarillion, explicitly written to be compatible with Catholic dogma. It's worth noting that all of Jesus's miracles can be performed, and in fact outclassed, at high levels by a perfectly mortal cleric. Well, except the dying to cleanse the world of sin one. But you can totally die and come back, if you do the prep work.
 * Averted in Scion. All of the Gods and Titans that show up are given their proper names from mythology. No monotheistic religions appear. Some still active religions are used, either Asian (Hindu pantheon, Japanese shintoism, a little traditional Chinese) or traditional European (Asatrú, Religio Romana, Celtic Heathenry, Slavic Heathenry and Druidism).
 * It's heavily implied that the titan Aten is, in fact, the inspiration for the Abrahamic god. His servants even look like angels. Moreover, an ancient conspiracy called The Order of the Divine Glory apparently runs all of the currently existing monotheistic religions from behind the scenes, and are behind the classic Catholic technique of sublimating other religious practices into their religion... all in an attempt to use the power of fatebinding to sublimate all gods, just as they did for the Sumerian storm god they already succeeded in enslaving.
 * Also Averted in earlier editions of Fantasy Games Unlimited's Chivalry & Sorcery. The primary religious pantheon was basically medieval Catholicism.
 * Priest characters had ranks that range from Friar up through Pope (with separate progression tables for Ordained vs Non-ordained). While clerics could not wield Magick, they could ask for Blessings. The Pope even has one called Crusade.
 * The demons also followed classical hierarchy, right up (down) to named powers and the Big Bad himself.

Webcomics

 * Sluggy Freelance did this with the Dimension of Pain, where hordes of demons are lead by the "Demon King" instead of the Devil, and were opposed by the "Goddess of Goodness" (who the Demon King kept locked in his freezer). Interestingly enough, Satan does exist in the Sluggy Freelance universe, as the father of 18 super-evil kittens. He is in charge of a different dimension, that does not feature as prominently as the Dimensions of Pain and Lame, so more of a case of 'the Devil is offscrene, but a analogue is'. God also made a brief Faceless appearance, just long enough to give Kiki a dire warning and pee on her head. Sluggy Freelance is that sort of series.

Western Animation

 * Disney studios used to be so cautious about religion that they coldn't even use the word "Bible". In the Johnny Appleseed segment from Melody Time, Johnny's cherished Bible was only referred to with the generic term "a holy book".
 * Rugrats had a few episodes based on Bible stories, including a Passover special. However, God is never mentioned; a burning bush talks to Moses/Tommy for no explained reason, and the parting of the sea at the end is a Deus-less Ex Machina. An episode about Noah's ark gives a vague comment about Noah being warned "from the Heavens."
 * Interestingly subverted in their Christmas Episode, where the babies come across a life-sized Nativity scene and admire what they think is a real baby. "Jesus" is still never named, though.