The free-exercise clause of the First Amendment states that the government “shall make no law … prohibiting the free exercise of religion.” Although the text sounds absolute, “no law” does not always mean “no law.” The Supreme Court has had to place some limits on the freedom to practice religion. To take an easy example cited by the Court in one of its landmark “free-exercise” cases (Reynolds v. U.S., 1878), the First Amendment would not protect the practice of human sacrifice even if some religion required it. In other words, while the freedom to believe is absolute, the freedom to act on those beliefs is not.

But where may government draw the line on the practice of religion? The courts have struggled with the answer to that question for much of our history. Over time, the Supreme Court developed a test to help judges determine the limits of free exercise. First fully articulated in the 1963 case of Sherbert v. Verner, this test is sometimes referred to as the Sherbert or “compelling interest” test. The test has four parts: two that apply to any person who claims that his freedom of religion has been violated, and two that apply to the government agency accused of violating those rights.

For the individual, the court must determine

• whether the person has a claim involving a sincere religious belief, and
• whether the government action places a substantial burden on the person’s ability to act on that belief.

If these two elements are established, then the government must prove

• that it is acting in furtherance of a “compelling state interest,” and
• that it has pursued that interest in the manner least restrictive, or least burdensome, to religion.

The Supreme Court, however, curtailed the application of the Sherbert test in the 1990 case of Employment Division v. Smith. In that case, the Court held that a burden on free exercise no longer had to be justified by a compelling state interest if the burden was an unintended result of laws that are generally applicable.

After Smith, only laws (or government actions) that (1) were intended to prohibit the free exercise of religion, or (2) violated other constitutional rights, such as freedom of speech, were subject to the compelling-interest test. For example, a state could not pass a law stating that Native Americans are prohibited from using peyote, but it could accomplish the same result by prohibiting the use of peyote by everyone.

In the wake of Smith, many religious and civil liberties groups have worked to restore the Sherbert test — or compelling-interest test — through legislation. These efforts have been successful in some states. In other states, the courts have ruled that the compelling-interest test is applicable to religious claims by virtue of the state’s own constitution. In many states, however, the level of protection for free-exercise claims is uncertain.