Religious Horror

1. A subgenre of Horror that relies on presenting the motifs of a real-life religion as fact within the story's universe. Since this is mainly a Western subgenre, that religion is Christianity (well, the only denomination that Hollywood knows of, at least).

Satan is the Big Bad in a typical Religious Horror story, although he's rarely shown. He is mediated through a human vessel, such as a Creepy Child or a degenerate rock musician. The protagonists are usually innocent people trying to live ordinary lives, not sensing anything wrong until their daughter or son starts speaking in someone else's voice, using foul languages she or he never studied, spewing Finnish pea soup, and/or chanting Satanic praises. Members of the clergy (most likely the Catholic variety; in this case it is justified by the fact that the Catholic church, of all the few that employ exorcism, is the most noted, although it does so very rarely) intervene eventually, with varying degrees of success. If there are human villains, they're evil cultists who facilitate Satan's activity on Earth (or, rarely, the Puritans of Salem, Massachusetts, if the author is less favorable toward organized religion in general). A variation is a woman giving birth to Satan's child. This type of horror is often written just to cash in on the popularity of The Exorcist.

2. Occasionally, the story revolves around a Religion of Evil that has nothing to do with Satan, which may or may not replace him with an Expy in the form of a God of Evil. These tend to be more creative than the Christianity-based novels, but not necessarily more bizarre, as you'll see.

3. Very rarely, you get a film that actually bothered to do the research, and includes horror either from the point of view of some religion other than Christianity, or more commonly have another religion as an antagonist. In the former cases, even if the movie itself is bad, the concept is very interesting. In the latter case, it ends up a variant of type 2, with the added problem of sounding like something from Chick Tracts.

Contrast Cosmic Horror Story, which is mutually exclusive with the first type of this subgenre. If a Cosmic Horror Story's Eldritch Abomination is worshipped as a god, then the story can fit into the second type.

See also The Bible, which is filled with taboo sex and merciless violence, sometimes sandwiched together.

Anime and Manga

 * Arguably, Angel Sanctuary, which is also a subversion in that the demons are neither good nor evil and the Big Bad
 * Bible Black
 * For Western audiences, Neon Genesis Evangelion has some elements of this, primarily because it takes Christian/Jewish symbols traditionally associated with good (crosses, Angels, haloes, etc) and turns them into symbols of fear.

Comic Books

 * Many of the early one-shot Hellboy stories revolve around this, particularly The Chained Coffin. Has become less prominent in recent years, as subsequent story arcs have revealed more of the Hellboy-verse's cosmology, which is more like a mix of Gnosticism & 1920s weird pulp fiction than Christianity.

Film

 * William Blatty's The Exorcist, as noted above.
 * Ira Levin's Rosemarys Baby.
 * The Omen. Because of this movie, many people think that the name Damien means "demon." It actually means "tame," which is used in the story in the sense meaning "kill."
 * The Exorcism of Emily Rose
 * Oddly enough, the Babylon 5 direct to DVD movie: "The Lost Tales," in which a maintenance worker is possessed by what is implied to be a literal demon, but specifically not the devil, rather a lower ranking servant. Colonel Lochley calls an exorcist.
 * Subverted because
 * Given that B5 Earth has been visited by Sufficiently Advanced Aliens at least once for a sufficient timespan to leave their marks in the human genome in the distant past, whether the 'demon' was a literal one or whether literature in turn and the practice of exorcism were inspired by events caused by him and his friends -- whatever kind of entity they might 'really' be -- hanging out on the planet since who-knows-when remains somewhat inconclusive.
 * The Backstory of B5 does seem to imply that demons were memories left behind by The Shadows.
 * ~The Devil's Advocate~ featured Satan (Al Pacino) in the form of the head of a New York law firm, and the protagonist (Keanu Reeves) is.
 * Constantine, the In Name Only movie adaptation of Hellblazer.
 * Touch of Satan
 * The House of the Devil deals with babysitter and a group of Satanists.
 * The Last Exorcism
 * In Zombie Cult Massacre, a sleazy cult leader pretends to be a compassionate man of God but is really in league with Satan, raising an army of zombies. It does not end well for him.
 * The Prophecy (1995) and its two sequels. About another war in heaven with Christopher Walken (who's creepy enough even when he isn't acting) as the Archangel Gabriel.
 * John Carpenter's Prince of Darkness, about a bunch of theology students trying to stop the Anti-Christ from releasing his father, the Anti-God.
 * Kinda. Prince of Darkness is actually a fun exercise with or Deconstruction of the Religious Horror subgenre, because most of the characters weren't theology students. Instead they were scientists of one kind or another, four or five of which were under the direct tutelage of a physics professor who had been selected for a series of televised debates with a Catholic priest because of his philosophical beliefs on science. Those debates happened before the story begins, and the two characters seem to be very good friends when the movie starts. To be fair, when speaking of said professor, one student said that "he wants philosophers, not scientists," so it is a little open to debate or interpretation.
 * The LDS-made film Brigham City uses elements of religious horror based on the LDS faith and puts them to work quietly in the background. This makes the film jarring to members of the LDS church without being over the top.
 * Also the LDS-made WWII film Saints And Soldiers, in the context of Deacon's hallucinations (the only character implied to be Mormon). Understandable in that he.
 * "The Shrine" has an interesting twist. At first, the viewer believes the small Polish village is involved in Satanic rituals with Human Sacrifice, but it turns out that they are only exorcising the tourists who unknowingly approach a demon statue that possesses them
 * Sin Eater, also known as The Order, starring Heath Ledger.
 * Stigmata, starring Gabriel Byrne as the protagonist, Father Andrew Kiernan.
 * End of Days, statting Gabriel Byrne as The Devil, and Arnold Schwarzenegger as the protagonist Jericho Cane, a retired cop.
 * The Seventh Sign, starring Demi Moore and Michael Biehn
 * From Hell, starring Johnny Depp, Based on the epinymous comic book series.
 * Bless the Child, starring Kim Bassinger

Literature

 * Dennis Lehane's Darkness, Take My Hand features a trio of serial killers who model themselves on the Holy Trinity and crucify all of their victims before killing them.
 * The Cthulhu Mythos often falls into the Religion of Evil version below, but even its official stance is this. There is no God, nor is there a Devil. There are entities of tremendous power such that humans would call them divine and deific, but these entities, due to their power, have no more concern for humanity than humanity as a whole would care for a dust-scurrying bug. Morality is a human creation, and humans are most certainly not special. Humanity must make worth of their own life, they have no inherent worth as a race.
 * "Officiality" is a bit subjective where the Mythos is concerned, however, as a lot of figures in the canon (perhaps most notably August Derleth) have put a more humanistic and/or Judeo-Christian spin on it.
 * Parodied in the Gaiman-Pratchett collaboration Good Omens.
 * David St. Clair's The Devil Rocked Her Cradle, a ceaselessly entertaining book that should probably not be sold as nonfiction. A young man kills his father, bruises a prostitute, rebels against his Catholic upbringing, becomes a thief, and hears demonic voices. He grows up to be an abusive husband whose daughter goes through on-and-off Satanic possession, especially after her newly widowed father starts living with his wife's sister. This leads her to projectile-vomit green stuff, recite Madness Mantras, and gesture obscenely at nuns and priests. It's Better Than It Sounds because it's So Bad It's Good. (The book's preface even includes the pricelessly redundant line, "[T]his book is not intended to be anti-Christian or pro-demonic.")
 * Jeffrey Sackett's Candlemas Eve, a fun fiction novel about a rock band that adopts two self-proclaimed witches to add something unusual to the act (plus, Evil Is Sexy). They turn out to be
 * John Saul's Punish the Sinners is a subversion:.
 * M.G. Lewis' Ambrosio, or the Monk, which not only makes this trope Older Than Radio, but manages to subvert it massively!
 * Petaybee: Shepherd Howling's Nightmare Fuel cult is heavily influenced by Christianity, most evidently in the title "shepherd".
 * Arthur Machen's "The White People" is a vastly more subtle example than most. The story combines The Fair Folk, Eldritch Location, Ultimate Evil, and Children Are Innocent with references to classic narrative poems to create a covertly religious horror tale. However, the frame story, in which one gentleman discusses the "infernal miracle" with a friend of his, reveals that Satan is afoot in the woods explored by the young heroine.
 * Robert Anton Wilson's The Masks of Illuminati reads like a rather moralistic Religious Horror story right up until the very end, but if you're at all familiar with Wilson's other works, you should know that things aren't going to be that simple. Lets just say that it takes the Unreliable Narrator to new heights.
 * The Blood Of The Lamb starts out rather mild, with a priest (Peter Carenza) discovering that But it gets worse. After, and by the end he manages to scare the ever-loving shit out of a pair of Jesuit assassins, , and has pretty much become the
 * Many of Frank Perretti's novels have elements of this, one of the most prominent being, "The Visitation."
 * Graphic depictions of Rapture fiction like Left Behind and Christ Clone Trilogy series can easily become this, whether intended by the author or not.

Live Action TV

 * This trope is the very essence of Carnivale
 * Seasons 4 and 5 of Supernatural, what with the impending apocalypse and all.
 * The X-Files had its share of this. All Souls is a good example.
 * "A Haunting," which aired from 2005 to 2007, was a series of reenactments of "true" ghost stories.

Music

 * Black Sabbath's "War Pigs" was originally written as "Walpurgis," which was recorded but never released. Hence, why "War Pigs" contains references to witches and Satan.

Tabletop RPG

 * KULT is a good example.

Video Games

 * Easier for Westerners to get than the Higurashi example below, its sister series, Umineko, uses many different motifs from the Bible, including having characters with names related to Biblical characters' and blood runes written near murder sites with passages from the Bible written around them in Hebrew.
 * The Binding of Isaac.

Web Comics

 * Silent Hill Promise seems to be crossing into this, especially in the church.

Web Original

 * While it's not immediately obvious, quite a few SCPs are clearly Judeo-Christian entities, such as Dr Clef's proposal for SCP-001, an angel guarding the Garden of Eden.
 * The angels in Requiem Aeternam are.
 * The Fear Mythos gives us the Archangel, which is basically the ultimate perversion of Judeo-Christian beliefs regarding God and the afterlife.
 * In "Heaven", a man dies and learns that eternal life in Heaven may not be all it's cracked up to be.
 * "Five Visions of the Ascetic" introduces us to a future version of Christianity devoted to the brutal weekly execution of a criminal codenamed "the Ascetic," who dies for our sins.

Comic Books:

 * Termight from Nemesis the Warlock is pretty much this, with religion worshiping Hate To All Aliens. It was based on Spanish Inquisition.

Film

 * The original version of The Wicker Man has  The protagonist is a devout Protestant, and a bit of an asshole, but by the end, he's become very sympathetic.
 * Interestingly, the ending of the original was almost meddled to have . This was cut because it clashed with the whole point. A deleted scene showed that  but it was deleted to leave the ambiguity in place.
 * Children of the Corn featured a cult based around "He Who Walks Behind the Rows," revealed at the end of the story to be a demonic-looking monster. In the movie versions, it's revamped to be an entire, nearly omnipresent (within and around the town) spirit whose influence increases when it starts to get dark. Though it is implied to be a devil-worshiping cult, it is never outright stated to be a demon OR Satan. It's referred to with pronouns by those who don't worship it.
 * Not exactly treated as a religion of evil, Voodoo is not framed in the best light in The Serpent and The Rainbow.

Literature

 * Craig Skipp's and John Spector's The Scream, a novel that uses the Satanic Panic as a backdrop. The novel revolves around the titular rock band, which is accused of being Satanic, but.
 * William Gladstone's Cat's Cradle, which is about an ancient cult whose religion revolves around Half Human Hybrids. The cover is pure distilled Nightmare Fuel, and the novel itself is extremely violent.

Tabletop Games

 * The Warhammer 40000 setting occasionally veers into this; there's an entire chapter of the Inquisition devoted to hunting down Daemons and banishing them back to the Warp, supported by a specially-trained chapter of the Space Marines.
 * Said Space Marine chapter number is 666.
 * The entirety of the Imperium of Man has religious overtones, from the ten-mile-long space cathedrals with broadside guns to the priests that inspire the Imperial Guard to heights of courage to the flamethrower-wielding power-armored nuns.

Video Games

 * The Silent Hill games have this for the cult that summons/awakens the town's latent evil. The movie goes with vaguely Christian religious fundamentalists.
 * Xenogears has an entire Religion of Evil to start, but it gets worse towards the end when you discover.
 * Somewhat closer to Type 1,
 * Resident Evil 4, the Los Illuminados cult mixes this with traditional zombie-styled horror.
 * Blood, anyone?

Web Original

 * Again, the SCP Foundation have a few of these, most notably SCP-231-7.
 * Archangel from The Fear Mythos embodies this for all religions..
 * This was also a central theme of The Refugees, a Slenderblog revolving largely around a Fundamentalist Christian sect who believed the Slender Man was an angel. It was the central theme of supplementary story The Transcend Manuscript.

Film

 * The Taiwanese film Double Vision is a religious horror in Taoist setting.
 * Jigoku, a depiction of Buddhist Hell.
 * Feng Shui (not to be confused with the tabletop game of the same name) is a movie of Taoism in the predominantly Catholic Philipines. A woman finds a ba gua mirror, which brings her luck, though the source of her good luck is a tradeoff, sacrificing her neighbors and loved ones in order to bring her material fortune.
 * Ghouls (2008) is from the perspective of Celtic Druids. Don't ask me what they're doing in what appears to be Eastern Europe, but it's an interesting film.

Video Games

 * The Wii survival horror game Cursed Mountain plays with the taboos, traditions, and underlying horrors of Himalayan Buddhism as its central theme.
 * Although most western viewers (and probably the rest of the non-Japanese audience too) don't get it, part of the horror of Higurashi no Naku Koro Ni for Japanese viewers comes from the Shinto temple with a history of human sacrifice. Shintoism places a high emphasis upon "purity." Shedding blood in a religious context is anathema to Shinto, as is touching corpses and bodily wastes. That Rika's ancestors (beware, really gross) makes their religion as much an inversion of Shinto as Satanism is an inversion of Christianity. To western viewers, it's merely disgusting. To believers in Shinto, it's beyond blasphemy, much like sacrificing a pig on the altar of the old Temple in Jerusalem.
 * There are lots of stories in Shintô about villages and shrines that did practice human sacrifice as a part of the religion. Mostly they tend to be moral parables of why this is not a good idea, though.
 * For added irony, Oyashiro self is NOT happy with it.
 * Ditto with the Fatal Frame series, especially with the first and second titles. In Shinto, some deities are malevolent and must be placated, but the All-Gods Village take it to a whole new Squicky level, with a Human Sacrifice ritual gone horribly, horribly wrong. It's like a follower of an Abrahamic religion having to fight his or her way through an entire village of Satan-worshippers.
 * With the exception of Mask of the Lunar Eclipse, the series feature Human Sacrifice in order to keep some sort of Hell Gate sealed up. Fatal Frame 2's sacrifice is probably the least Squicky of the examples (Fatal Frame 1 involves a Virgin Sacrifice being torn apart by ropes attached to her legs, arms, and neck. Fatal Frame III is much worse.)