Generally includes the rights guaranteed by the Constitution under both the First Amendment’s free exercise clause and its establishment clause. The free exercise clause enables a person to hold whatever religious beliefs he or she wants and to exercise that belief by attending religious services, praying in public or in private, proselytizing or wearing religious clothing such as yarmulkes or headscarves. Also included in the free exercise clause is the right not to believe in any religion and the right not to participate in religious activities.
Second, the establishment clause prevents the government from creating a church, endorsing religion in general, or favoring one set of religious beliefs over another. As the Supreme Court decided in 1947 in Everson v. Board of Education of Ewing Township, the establishment clause was intended to erect “a wall of separation between church and state,” although the degree to which government should accommodate religion in public life has been debated in numerous Supreme Court decisions since then. – The United States Constitution, What It Says, What It Means, A Hip Pocket Guide