“It is a permissible reading of the [free exercise clause]…to say that if prohibiting the exercise of religion is not the object of the [law] but merely the incidental effect of a generally applicable and otherwise valid provision, the First Amendment has not been offended….To make an individual’s obligation to obey such a law contingent upon the law’s coincidence with his religious beliefs, except where the State’s interest is ‘compelling’ – permitting him, by virtue of his beliefs, ‘to become a law unto himself,’ contradicts both constitutional tradition and common sense.’ To adopt a true ‘compelling interest’ requirement for laws that affect religious practice would lead towards anarchy.”
Employment Division v. Smith