Scam Religion

Looking for heaven in all the wrong places, Bob has found a religion that seems to have all the answers. But the faith he has found is really just an empty shell: A scam, a whole lotta nothing, a glaring emptiness hiding behind a paper-thin façade of superficial wisdom.

The teachings and followers of the Scam Religion are not evil, it's merely a matter of wasting time and resources. In a setting where there is One True Religion, the greatest crime of the Scam Religion is to keep people distracted, thus preventing them from accepting the true salvation. In a setting where there isn't One True Religion, then the Scam Religion is, well, a scam, and not anything more harmful than that - not that a scam is harmless...

The founder of the religion is another matter. He might be outright evil, an immoral Con Man, the victim of a Strange Pond Woman, Ignorant of His Own Ignorance, crazy, an unwilling victim of his own hype, a person who has brainwashed himself into believing his own empty hype, all of the above, or whatever. However, if he's still around, he does not (usually) use his cult for purposes more nefarious than getting undeserved admiration, money, and sexual encounters from his followers.

In a Low Magic World, a Scam Religion typically has no power at all. In a High Magic World, it will have power — but its power will be empty, inferior, low level. Arcane tricks rather than true divine miracles.

Often a Parody Religion. See also Church of Happyology and God Guise. Contrast Path of Inspiration, where the cult members are Obliviously Evil Mooks of some kind of Evil Overlord or Ancient Conspiracy, and Scary Amoral Religion, which leads its followers into depravity.

NOTE: Only add examples that can be objectively verified to be scams according to the narrative.

Anime and Manga

 * Fullmetal Alchemist: The Church of Leto, led by Father Cornello, who gathers followers in Lior by convincing them he can do amazing miracles with power given to him by the sun god, Leto. In reality he's just a regular alchemist (and not even a particularly talented one), albeit one with a Philosopher's Stone that enhances his alchemy. Edward uncovers the scam very early on in the manga. Much, much later, we find out he was going to use his follower's souls as part of the Gambit Pileup orchestrated by the Big Bad.
 * It's implied that the Ishvalan religion was invented by in order to have an easy genocide target when the time came. Of course, its also implied that this god intervened in the fight between  and Scar, blinding the former with a ray of light at a key moment, so who knows.
 * The Tatami Galaxy has a combination religion/pyramid scheme.

Comic Books

 * Fables: in The Great Fables Crossover, the belief in Blue Boy temporarily turns into this as Jack takes over as its shepherd.

Film

 * In Leap of Faith, Steve Martin's character is a self-confessed Con Man who sees religion simply as a way to scam the people who attend his revival meetings. However, he's forced to rethink his views on religion when

Literature

 * The Chronicles of Narnia: The seventh book features a monkey trickster who makes people believe in a fake Aslan that is really a donkey in a cheap lion costume.
 * Scientology? Nothing to see here. There's Fosterism in Stranger in A Strange Land.
 * Ironically, though Fosterism was founded by scam artists looking to get paid (and laid) by gullible people, their Supreme Bishops
 * Bokononism in Cat's Cradle. Quite openly.
 * Hillman Hunter of And Another Thing has one of these and is shocked when the apocalypse he's been preaching not only happens, but his cult is let off the planet in time, which (at least superficially) is just as he predicted.
 * In the Doctor Who Missing Adventures novel The Crystal Bucephalus, the Lazarus Intent was deliberately founded by a Con Man as a source of suckers who would bail him out when he finally got himself into real trouble.
 * The book Leaving Fishers by Margaret Peterson Haddix is about a girl who joins a cult called Fishers of Men. Among the many other things wrong with it, one thing she finds out at the end  is that the head of the cult is using their donations to support a lavish lifestyle, while making it out as though he can barely afford things.
 * In The Bible, Moses exposes the polytheism of Egypt as a scam religion by calling down ten plagues. Each plague is directed against one major Egyptian deity, but each time the polytheistic priesthood is unable to stop the plagues - thus proving that the God of Moses is the true God.
 * Fighting a scam religion forms the main plots of books eight and nine of Ranger's Apprentice.

Live-Action TV

 * The Sliders episode "Prophets and Loss" has a fundamentalist church which "sends its believers to paradise" with what the protagonists think is Sliding technology.
 * Law & Order: Special Victims Unit the SVU team take on a cult leader, who brainwashes women into his cult by making them his wives so he can get access to their bank accounts.
 * If it's the same case I'm thinking of, said cult leader also brainwashed married women and their husbands into becoming part of the cult. Then he'd secretly kill off the husbands and convince the wives that the guys had abandoned them, thus mind-controlling the women even more.
 * Stargate SG-1 dealt with destroying many of these, from the parasitic Goa'uld, to the demigodlike Ori, and even a few fringe cults, like the time an SG team member went crazy/rogue and declared himself a god.

Radio

 * Hudson and Landry's "Fredrickism" skit; involving the worship of creator Freddie Schultz, obeying the 26 Commandments grants you immortality, and under investigation by the IRS.

Tabletop Games

 * Transhuman Space, with its memetic science, has several bizarre religions, most of which are at least partly engineered. Some of them are genuine, at least one started as a joke that got out of hand, and then there's things like Ecoherence, which is pretty close to being an eviromentalism-themed Church of Happyology, carefully designed to create "self-reinforcing cycles of dependency", and charging for brain-scans to judge how "coherent" its followers are. And the Unified Way, which was created as a weapon.
 * Dragonlance had the Seekers, who used the void left after the gods abandoned the world in the wake of the Cataclysm to seize power by peddling false religion.
 * Pathfinder features the Church of the Living God, a Cult run by a man in God Guise who employs mages disguised as priests to enforce his will.
 * BattleTech's pre-schism ComStar (and after the split, Word of Blake) has aspects of this. Heavily shrouded in mysticism towards outsiders and definitely capable of inspiring religious fervor in its own members as well, ComStar is fundamentally just an Ancient Conspiracy hoarding technological know-how and waiting for the Successor States to bomb themselves so far back into the Stone Age that they can step in and take over for the ostensible good of all mankind. (They're not above stirring the pot themselves if it looks like things might actually settle down or quietly eliminating outsiders who might be on the verge of making scientific breakthroughs, either -- since they just so happen to control most interstellar communication under the guise of neutrality, they tend to be very well informed.) Interestingly, this is by many accounts not what ComStar's founder ever intended, for all that many members of the organization are prone to dropping supposed pearls of his wisdom into conversations at every opportunity; it's only under his successor that things rapidly started to take on a religious bent.
 * The classic Dungeons and Dragons adventure The Temple of Elemental Evil was this twice-over. Most cultists believed they were simply worshiping the destructive powers of the elements. However, it was actually a ruse by the demon lord Zuggtmoy, who designed the ruse in order to better recruit worshipers and gain power; few mortals worshiped her directly, because a goddess of fungus isn't all-too appealing.
 * The cult of the god Zhakata in the realm of G'Henna, from the Ravenloft setting is one of the worst examples of this trope in RPGs (possibly the worst example period). Zhakata is a god of famine and most of the food produced in the realm is sacrificed to him (and actually eaten by the corrupt priesthood, naturally). His worship involves voluntary human sacrifice via starvation, among other such pleasant things. Worshippers hope that their sacrifice will mean that Zhakata will transform from his evil Devourer aspect to his benevolent Provider aspect, and reward them with an era of bounty. The thing is, even in-universe Zhakhata isn't real (Ravenloft itself grants spells to the cult's leaders), so people are killing themselves for no reason in hope that a fictional savior will come. Zhakhata is actually a delusion of Yagno Petrovna, the high priest. Yagno is aware on some level that his god doesn't really exist, and part of the Ironic Hell he has to suffer as a Darklord is living in doubt that his lifelong faith is a sham. Despite this, he  chooses to continue to delude himself and promote Zhakata regardless. This willingness to let people suffer and die for a lie is what keeps Yagno as the Darklord of G'henna.

Theatre
"And the voice said, "Brother, there's a million pigeons Ready to be hooked on new religions.""
 * The Rhythm of Life Church in the musical Sweet Charity. It was supposedly founded at the urging of a mysterious Voice:

Video Games
"Minato: You're scamming them, too?"
 * Fall From Heaven has a spirit magic user in the backstory who regularly did this.
 * Fable II features T.O.B.Y., the Temple of Business and Yodeling, also known as the Temple of Benevolent Yokels. A quest in Bloodstone involves you running errands for the founder, Toby, but you eventually find out it's just a front for Toby to find suckers he can con into buying useless crap or running errands for him.
 * And hookers. Don't forget the hookers.
 * In the first game, the backstory reveals that both Avo the God of Good and Skorm the God of Evil are fakes invented by an enterprising merchant as a way of collecting money from the donations of followers. The scam works because their temples are built over places of very strong naturally occuring magical energy, so the power itself is real, even though the deities themselves are not.
 * Deus Ex Invisible War has the order, a front for the illuminati created for the sole purpose of unifying all religion. Aside from the leader herself everyone thinks it's the real deal, even the leader's second-in-command.
 * Grand Theft Auto Vice City has Pastor Richards, who is raising money for a Salvation Statue to save himself and his followers from the apocalypse. He admits on the radio his plan to use the statue money to build a mansion in Hawaii.
 * Final Fantasy X has the Church of Yevon. It teaches that Sin was a divine punishment for using machina, that machina weapons are evil, that Sin will go away with enough prayer and repentance, and that the Final Summoning can free the world from Sin. While it's true from one point of view that machina brought about Sin (Bevelle won the war because of their superior weaponry, and Yu Yevon created Sin as his revenge), they are not inherently evil and Sin is not divine; the church uses this lie to keep the populace under control (no advanced weaponry = harder to overthrow the church). Sin will not go away with any amount of prayer or repentance, and the Final Summoning is actually how Sin is reborn; this lie is used to give the people false hope and keep them ignorant of the true state of things. It's made very clear that the Maesters are fully aware of the continued lies they spread.
 * The usual game plan of the Big Bad of the last four Ultima games. The most obvious example is the Fellowship in Britannia, but he pulls the same trick in at least three other worlds to weaken them for conquest. Where he succeeds the scam quickly metamorphoses into a Religion of Evil.
 * In Persona 3, the Moon Social Link for Minato at one point requires a "salvation fee" of 320,000 yen You can even later call out the person you share the link with.

Web Comics

 * The Church of Wayne in Scary Go Round is really just a con to net money and women for Wayne.

Western Animation

 * Movementarianism from The Simpsons (which is also Happyology).
 * South Park has portrayed both Scientology and Mormonism is this way. Ironically, other episodes have shown that Mormons are the only people who get into Heaven, so it's not taking itself that seriously.
 * That said, the episode about Mormonism was pretty much entirely "Woah, Mormonism is a load of bull -- but Mormons are the sweetest people on Earth, so who cares?"
 * Chip 'n Dale Rescue Rangers once had Gadget half-heartedly attempt to join a soda-worshiping cult of mice. The evil second-in-command of the cult was using all the belongings new members gave up and keeping them.
 * Sympathetic example: in the Avatar: The Last Airbender episode "The Painted Lady", starts one of her own. As she helps some villagers, they mistake her for their local deity—and instead of trying to clear up the mistake, she chooses to make the most of it, turning herself into a false deity for them to worship. Of course, the villagers are outraged when they find out that she has deceived them, but they quickly forgive her since they realize that the help she gave them was genuine rather than part of some manipulative plot..
 * In Prince of Egypt, this is how the Egyptian mythology is portrayed. The High Priests replicate Moses' stick-to-snake miracle, but it's all about creative lighting, ominous statues and chanting, sleight-of-hand tricks and a big helping of showmanship. While Rameses is impressed, he fails to notice that Moses' snake devours the priests' snakes during the Villain Song. The priests are later exposed when they prove to be utterly useless against the Abrahamic God's ten plagues.