Secularism and theocracy
A commonly advocated position is that the government should be a secular institution; that is, have no state religion, have no legislation that outlaws or favors one religion over another, and have no religiously motivated regulations on the eligibility of the nation's politicians. A secular state has no power over the nation's churches and the nation's churches have no political powers over the members of the government. A related notion is the French laïcité.
Many Western democratic nations place a high importance of the separation of church and state. Some nations, such as the United States of America and Canada, even have specific clauses in their constitutions which are widely interpreted as forbidding the government from favoring one religion over another.
Other democracies, such as Argentina or the United Kingdom, have a distinction between church and state which is slightly more blurred. These nations have a constitutionally established State religion, but are inclusive of citizens of other faiths.
In countries like these, the head of government or head of state may be legally required to be a member of a given faith. Powers to appoint high-ranking members of the state churches are also often still vested in the worldly governments. These powers may be slightly anachronistic or superficial, however, and disguise the true level of religious freedom the nation possesses.
Secularists generally do not hold that the state must be atheist — that is, opposed to religion. However, traditionalist religious critics of secularism often consider secularism to be a departure from tradition in the direction of atheism. Those who believe that the state has religious obligations, or that it must be informed by religious values, often regard secularism as atheism.
The opposite end of the spectrum from secularism is a theocracy, in which a religion controls the government, and the rule of law is closely linked with the interpretation of a religious texts such as the Bible or the Koran. A few outright theocracies exist today, such as the Vatican or Iran, in which politics is either completely run by religious authorities or run only with its explicit consent. Arguably a few other nations in the Middle East have political policies which are often directly dictated or strongly influenced by religious leaders.
Many religions, such as Catholicism and Islam, hold that one must not separate Church and State. The Catholic Church's 1983 Canon Law proclaims that "Christ's faithful are to strive to secure that in the civil society the laws which regulate the formation of the young also provide a religious and moral education in the schools that is in accord with the conscience of the parents." 
Islam holds that all political life must exist within Islamic law. There is a contemporary debate in Islam whether obedience to God is ultimately compatible with the Western secular pattern, which separates religion from civic life, as opposed to Islamic ideals of toleration.
At the same time, some religions appear to advocate such separation. For example, many Christians, such as Jehovah's Witnesses, interpret Biblical passages such as Christ's admonition to "render unto Caesar that which is Caesar's" as a warning not to be involved in civil governments. One common theme among such religions is that the world and the government are hopelessly corrupt and that religious involvement in government would corrupt the religion more than it would save society.
Separation of church and state occurs in different ways:
Some countries of the world have a stable separation between church and state, while other countries are in a state of political unrest over the separation. The 1905 French law on the separation of Church and State started considerable controversy and even riots.
- legal separation
- voluntary separation, such as by churches teaching that religious ceremony should be confined to either the church or the home.
Separation of Church and State is a notion related to, but separate from, freedom of religion. There are many countries with an official religion, such as the United Kingdom or Belgium, where freedom of religion is guaranteed. Conversely, it is possible for a country not to have an official religion, or a set of official religions, yet to discriminate against atheists or members of religions outside of the mainstream. For instance, while the United States does not officially advance any particular religion, proponents of atheism were persecuted in many US jurisdictions in the 19th century.
There are different interpretations of the notion of separation of Church and State:
- one sees this separation from a legal and financial point of view: the State should not establish nor fund religious activities, and may even be prohibited from funding non-religious activities affiliated to religious organizations;
- another sees this separation in keeping religious beliefs out of the motivations of public policies, preventing interference from religious authorities into state affairs, and disapproving of political leaders expressing religious preferences in the course of their duties.