The Free Exercise Clause protects not just the right to believe or the right to worship; it protects the right to perform or abstain from performing certain physical acts in accordance with one’s beliefs. Federal statutes, including the Religious Freedom Restoration Act of 1993 (“RFRA”), support that protection, broadly defining the exercise of religion to encompass all aspects of observance and practice, whether or not central to, or required by, a particular religious faith.

From: Federal Law Protections for Religious Liberty