Freedom of religion or religious liberty is a principle that supports the freedom of an individual or community, in public or private, to manifest religion or belief in teaching, practice, worship, and observance. It also includes the freedom to change one's religion or beliefs, "the right not to profess any religion or belief", or "not to practise a religion" (often referred to as "freedom from religion").
Freedom of religion is considered by many people and most nations to be a fundamental human right. In a country with a state religion, freedom of religion is generally considered to mean that the government permits religious practices of other communities besides the state religion, and does not persecute believers in other faiths or those who have no faith.
Freedom of religion goes beyond freedom of belief, which allows the right to believe what a person, group, or religion wishes, but it does not necessarily allow the right to practice the religion or belief openly and outwardly in a public manner, which some believe is a central facet of religious freedom. Freedom of worship is uncertain but may be considered to fall between the two terms. The term "belief" is considered inclusive of all forms of irreligion, including atheism, humanism, existentialism or other schools of thought. Whether non-believers or humanists should be considered for the purposes of freedom of religion is a contested question in legal and constitutional contexts. Crucial in the consideration of this liberty is whether religious practices and motivated actions which would otherwise violate secular law should be permitted due to the safeguarding freedom of religion, such as (in American jurisprudence) United States v. Reynolds or Wisconsin v. Yoder, (in European law) S.A.S. v. France, and numerous other jurisdictions.
Historically, freedom of religion has been used to refer to the tolerance of different theological systems of belief, while freedom of worship has been defined as freedom of individual action. Each of these have existed to varying degrees.