Illegal Religion / Literature

• In Ananda's Fall, the psychiatrist Dr Piroozad fled Iran as a child as a result of persecution of the Baha'i faith by the Islamic Republic following the revolution.
• Averted in Joust. The Tians allow Altans in captured territory to continue to worship their own deities, to avoid the problems that would result from underground worship. (The fact that the Tian and Altan pantheons are almost identical doesn't hurt, either.)
• In David Eddings's Belgariad and Malloreon series, the Bear Cult, based on a misguided worship of the Alorn's god Belar, has to be periodically suppressed for its fanaticism.
  • In turn, the Bear Cults wants to do this the other Kingdoms of the West, forcing them to worship Belar as opposed to their own gods (or all of them in the case of the very ecumenical Sendars).
  • While the outlawing of the Bear Cult is the banning of a specific form of an accepted religion, a straighter example is the banning of the worship of Torak in all the Alorn Kingdoms. Similarly, in Mallorea, traditional Karand religion is banned, mostly because it involves the worshipping and summoning of demons.
• In The Witcher universe, Coram Agh Tera, the Cult of the Lionhead Spider, is a forbidden religion in many of the civilized nations due to its practice of Human Sacrifice, and while the persecution is not as intense as it has been in the past, very few places will allow Coram Agh Tera cultists to preach openly. The government of Temeria is particularly keen to suppress the cult within their borders, and membership of the Lionhead Spider cult is a crime akin to murder.
• In Discworld, both Omnia in Small Gods and Borogravia in Monstrous Regiment banned any religion other than the state one (Omnianism and Nugganism, respectively). Borogravia's neighbour and arch-rival Zlobenia banned the Nugganatic religion, which was probably for the best.
• Downplayed in the Star Carrier series, where the Terran Confederation's "White Covenant" law means that, while religion isn't banned outright, many of its common practices are. In particular, proselytizing, many missionary activities, and conversion by threat or force are considered violations of basic human rights. This came about after Islamic terrorists nuked several major cities and set off World War III, and understandably doesn't sit well with a lot of religious groups (the Muslims especially, since it bans a core tenet of the faith, to bring the word of Allah to the infidel).
• In The Immortals, Emperor Ozorne of Carthak restricted or discouraged traditional religious practices and tried to set himself up as an object of worship, but he stopped short of actually banning religion for fear the gods would take umbrage and depose him. He ended up pushing them far enough to put Daine in place to demolish his regime (and several palaces) with an army of animate dinosaur skeletons.
• In The Stars My Destination, religion has been outlawed and pictures of people practicing it in secret are treated as something akin to pornography.
• In 2230 in the novel Valhalla, all religion is banned without exception. The villains of the novel are colonialist missionaries.
• In the Left Behind series, Christianity as well as all other religions except for Carpathianism become illegal to practice during the latter half of the Tribulation when Nicolae Carpathia is "resurrected" and proclaims himself to be God. Surprisingly averted by God and Jesus Christ in the Millennial Kingdom, since they allow The Other Light members to practice their religion within certain limits.
• In Harry Turtledove's Colonization trilogy, the Race does not exactly outlaw human "superstitions" in their territories, but they do want to encourage conversion to their own reverence of the Spirits of Emperors Past. To accomplish this, they impose certain restrictions, such as charging people a fee to enter temples and forcing students in their medical school to pay respects to the shrine of the Spirits of Emperors Past. They have better success in China, where they managed to frame the practice in ways already similar to traditional Chinese ancestor reverence, and worse luck in the Middle East, where poor words from the Race ground troops make it a direct challenge to Islam.
• In Timeline-191, the US government faces rebellions from the Mormons of Utah during every war they fight with the CSA, with the Union Army crushing the rebels each time. This mirrors the real-life conflicts of the Mormons with the USA, and The Troubles. It's sparked by the federal government cracking down on their polygamy in 1881.
• in Cat's Cradle, every successive ruler of San Lorenzo outlaws Bokononism (and is an ardent Bokononist). It's actually an important part of the religion: since the poverty and relatively abysmal living conditions of the tiny nation and its populace really are pretty hopeless, the founder(s) of Bokononism decided that the religion should at least provide an interesting and entertaining drama to give the people something else to focus on. So, they took on the dual roles of the Holy Prophet in the jungle and the Evil Dictator in the city, eventually both succumbing to Becoming the Mask to one degree or another.
• In the United States of Christian Nation, all religions except for Christianity are banned.
• Annals of the Western Shore: In Voices, the Alds have outlawed worship of Ansul's Fantasy Pantheon. While they don't make any effort to evangelize their religion, they come down brutally on anyone they catch saluting one of Ansul's many religious statues or shrines.
• Christianity is, of course, an Illegal Religion in Search the Seven Hills. The Praetorian Arrius explains why; "They could sacrifice their babies in the forum if only they'd give a slice of the meat to the Genius of the Emperor. But they won't."
• The Baroque Cycle: Depending on where you are in Europe, either Catholicism, or some — or all — forms of Protestantism may be illegal. Some places switch back and forth multiple times over the course of the story.
• In the Final Empire of Mistborn: The Original Trilogy, all religions except for the Steel Ministry are illegal, as an extension of the fact that it's illegal to regard anyone but the Lord Ruler as a god. Even then, only the Obligators (the Ministry's priests and bureaucrats) are permitted to engage much in the ritual and spiritual side of the faith — the Lord Ruler prefers his followers to show more material forms of devotion.
• In the Malazan Book of the Fallen, Empress Laseen crushed the cult of War God Fener after she ascended the throne, and the only people seen worshipping him are either non-Malazans or Malazans who are willing to take the risk of persecution and worship him anyway.
• The Handmaid's Tale: Everything except the regime's particular fundamentalism is banned. Being a Catholic priest is a capital crime, and it's mentioned that the Church ordered clergy to stop wearing the cassock because of this. Quakers are also mentioned as being persecuted, along with Baptists (who have rebelled). Jews are allowed to convert or leave for Israel. Those who stay but practice Judaism in secret are executed.
• Underground Zealot: All religions have been banned, as religious conflict somehow started World War III.
• Dr Piroozad, the psychiatrist in Ananda's Fall, is a Baha'i refugee whose family fled severe religious persecution due to the Iranian Revolution.
• Caliphate: Following a nuclear attack by Islamic terrorists on the US, Islam is banned and all Muslims within its territories are displaced. Most of the world including the rest of the American continent, UK, Japan, China, and Australia follows suit, with the exception of the European Union, who turns into a Caliphate with the influx of Muslim refugees and them taking over. The only states where Muslims are tolerated under non-Muslims are Russia and South Africa, and even then, they are treated like second-class citizens where even African natives under apartheid are treated better.
  • Within the Caliphate, Christianity is tolerated, but it's also given second-class status to Islam. Christians are essentially slaves that can be killed at will, their testimony is half the weight of an Muslim, and proselytizing is punishable by crucifixion.
• The Marquis de Sade proposed this, saying that Catholicism should be eradicated in France with mass terror and violence. He wanted practicing it to be a capital crime, and replaced with atheism plus his own nihilistic philosophy which said basically "anything goes".
• In the new Star Wars Expanded Universe, the Empire is revealed to have prohibited organized religion, and more specifically belief in/worship of the supernatural generally. Of course, there were still many underground religions like the Church of the Force.
• Played with in the Dreamscape Voyager Trilogy. The widely held belief in the world is that the gods are universally evil, and spiritual leaders are dedicated to helping people 'avoid' them. However, while it is illegal to outright worship them, there is no law against painting a mural of one on the deck of your ship, naming your publically recognized mercenary band after one, or using their names to curse.
• The Reluctant King: The theocracy of Tarxia forbids every religion besides theirs. Foreign visitors who aren't converts are only permitted for short periods, having to wear placards reading "Licensed Heretic" while in Tarxia.
• The Tough Guide to Fantasyland: One feature of the monotheist religions if they are fanatical is suppressing all other sects.
• Terra Ignota: Except in designated Reservations, all organized religion is banned as a result of the Church Wars, to the point where simply discussing theology in a group of three or more people "unchaperoned" is specifically outlawed. Possessing religious iconography isn't illegal, but since those religions are taboo, nobody wants it anyways. However, non-organized religion is tolerated: to address peoples’ spiritual needs, which haven’t magically vanished, specially trained counselors called sensayers help them develop and practice one-person religions, individual to each of their clients.
• The Legend of Drizzt: Drow cities (at least Lolthite ones) ban worship of other gods. For non-Drow, the first offense means paying a heavy fine, the second death. For Drow, worshipping other gods is punishable by death no matter what.
• Swan's Braid & Other Tales of Terizan: In "The Things Everyone Knows" worship of Death itself has been banned in Oreen by the Council as rival sects caused trouble centuries before. Now only Ayzarua, who is the Gateway to Death, can be legally worshiped as she's different enough. Her followers maintain the Necropolis.
• Daughter of the Sun: Worship of Aelia, Goddess of Caprice, has been outlawed for centuries, as her influence causes people to do whatever feels good and thus neglect necessary things. Other cults to chaos gods are also outlawed from what's implied, though it isn't stated explicitly.