| It doesn't stop|
at the water's edge
A state religion is the endorsement or enforcement of a particular religion by a state.
This can be thought of as two positions; endorsement and enforcement. The former, endorsement, is benign for the most part. England, for example, has Christianity (specifically the Church of England with the Queen at its head) as its official state religion although in practice the country is almost entirely secular. The latter position, that of enforcement, is less benign because it leads to repression of other religions and lack of religion. Even today a number of countries have repressive policies regarding their state religion and severe punishments that may be meted out to those who break them. These are, for the most part, the Islamic fundamentalist states in the Middle East, such as Saudi Arabia, Iran and Syria. Some are surprised to learn that in Israel, Orthodox Judaism controls family law, and that the Orthodox rabbinate is state-funded; only Orthodox rabbis may legally marry people.
State religions have often been used to uphold nationalist regimes, such as Nazi Germany's use of "Positive Christianity" and the development of "State Shinto" in Imperial Japan. There is also the "Religion of the State" as exemplified in fascist Italy, Communist China, and formerly in the USSR.
- Argentina (Roman Catholicism)
- Denmark (Lutheranism)
- El Salvador (Roman Catholicism)
- England (Church of England, see below)
- Greece (Orthodox)
- Iceland (Lutheranism)
- Malta (Roman Catholicism)
- Norway (Lutheranism)
- Roman Empire from 380 CE (Nicene Christianity)
- Scotland (Church of Scotland (Presbyterianism))
- Holy See (Vatican City) (Roman Catholicism)
- Brunei (on 1 May 2014, strict sharia law was introduced and applies to both Muslims and non-Muslims)
- Iran (specifically Shia)
- Saudi Arabia
- United Arab Emirates
- Aceh (part of Indonesia)
- Parts of Somalia are de jure secular but de facto ruled by theocratic courts
- Several states of Nigeria
Orthodox Judaism (only applies to Jewish population)
- Pre-WWII Japan
- Albania (banned all religious practice 1967–1990)
- China
- North Korea
- The former USSR
These countries, among others, have officially enshrined freedom of religion:
- Belgium (even if it came multiple times under fire from ruling Catholics)
- France (staunchly so)
- Germany (less staunchly so, see below)
- New Zealand
- South Africa
- South Korea
- Sweden (after having a Lutheran state church up to 2000)
- United States (thanks Mr. Jefferson)
Weird borderline cases
Many states, while not having a state religion, are not precisely secular either. This ranges from mention of "god" in the constitution, e.g. Poland, Germany, Hungary and Canada on the one hand, to on the other state-funded religion classes in public schools, e.g. Belgium  and the state paying the upkeep of religious infrastructure. Also, these in-between countries can pay the wages of priests and ministers or even collect tithes for the church as in Germany. While "radical" atheists often advocate for full secularism and try to repeal these laws and those prohibiting "blasphemy," religious advocates often defend these statutes with non sequiturs such as: "It's not as bad as Saudi Arabia."
Israel also falls in this category; despite being a Jewish state, its laws are mostly based on secular principles with contentious exceptions -- mostly in family law. This issue is as much a political football as prayer in public schools or gay marriage have been in the US. Israel has no civil marriage but secular and leftist parties want to introduce it, while Likud and religious parties remain opposed. Israel does, however, recognize marriages (including same-sex marriages) that were validly entered abroad.
The state religion or Established Church of England is "The Church of England" or "Anglican Church", familiarly known as the "C of E", and was founded by Henry VIII to get around the papal ban on his desires for possible manchild-bearing spouses. Said Henry became officially "of the Church of England in Earth Supreme Head" in 1535. Take that, assorted Bishops of Rome.
Some senior clergy actually have the right, by virtue of their job, to sit in the upper house of the legislature (House of Lords). The bishops of the C of E are also (nominally) selected from a shortlist by the monarch (in fact, by the Prime Minister). (The other methods of gaining entry to the House of Lords - originally gained by virtue of their birth - are, of course, perfectly legitimate.)
The fact that the religion is officially part of the government gives the clergy an influence out of proportion to the active popular support for their denomination, but nobody takes any notice of them so it doesn't matter.
The word antidisestablishmentarianism, once the longest word in the OED, was coined (allegedly by future Prime Minister William Ewart Gladstone) to refer to opposition to disestablishing the Church of England.
Note that the Church of England is established in England only and not in the rest of the UK (plus the Isle of Man and the Channel Islands). The Anglicans became disestablished in Ireland and in Wales after low take-up by the populations there. Anglicanism has never been established in Scotland (it being a separate kingdom during Henry VIII's time and all). As for the "C of E" in other outposts of The Empire ... Canadian Anglicans officially stopped calling themselves "the Church of England in the Dominion of Canada" as early as 1955.
The US specifically doesn't have a state religion, with the establishment clause of the First Amendment saying "Congress shall make no law respecting an establishment of religion" - commonly referred to as the separation of church and state, although the phrase derives from a letter by Thomas Jefferson and is not found in the law itself. Despite this, many on the Religious Right believe the US was established as a Christian nation, and actively support state sponsored religion, including using the Ten Commandments as a basis for law and displaying them prominently in public.
- BBC report of Christian charity Tearfund's survey
- Technically. The High Court, led by Lionel Murphy, a pissed-off atheist, ruled that the government couldn't declare what was and wasn't a religion, which is why it's one of the countries where Scientology is a tax-exempt religion. Murphy suggested that if they didn't want to give Scientology a free ride, they should stop the tax exemption of religion in general.
- Although the Charter of Rights and Freedoms mentions God in the preamble, it also guarantees the freedom of conscience and religion. There is no established church.
- It should be noted though that in the case of Belgium state-funded classes on Christianity are about as publicly funded as classes on atheism, Judaism, Islam, Sikhism and irreligion. Classes on other religions than those mentioned may however be out of luck.