The First Amendment to the United States Constitution makes it unlawful for the U.S. Congress or any of the states to prohibit the free exercise of religion.

The free exercise of religion means the right to believe and profess whatever religious doctrine one desires. Thus, the First Amendment obviously excludes all governmental regulation of religious beliefs. The government may not compel affirmation of religious belief, punish the expression of religious doctrines it believes to be false, impose special disabilities on the basis of religious views or religious status, or lend its power to one or the other side in controversies over religious authority or dogma.

But the exercise of religion often involves not only belief and profession of belief, but the performance of (or abstention from) physical acts: assembling with others for a worship service; participating in sacramental use of bread and wine; proselytizing; or abstaining from certain foods or certain modes of transportation.

A State would presumably be prohibiting the free exercise of religion if it sought to ban such acts or abstentions only when they are engaged in for religious reasons, or only because of the religious belief that they display. It would be unconstitutional, for example, to ban the creation of statues that are to be used for worship purposes, or to prohibit bowing down before a golden calf.

In California, as in all states, the First Amendment to the United States Constitution provides robust protections for the free exercise of religion. This means that individuals have the right to hold any religious belief they choose, and the government cannot compel them to affirm any religious belief, punish them for their religious expressions, or impose special disabilities based on their religious views or status. Furthermore, the government cannot favor one religion over another in disputes about religious doctrine. The free exercise clause not only protects beliefs but also the performance of acts associated with those beliefs, such as worship services, sacraments, proselytizing, and dietary practices. California must not prohibit religious acts or abstentions solely based on their religious nature or the beliefs they represent. For example, the state cannot ban the creation of religious statues for worship or prohibit certain religious practices like bowing to religious symbols. Any such law targeting religious practices would likely be deemed unconstitutional under the First Amendment.