What make someone a member of a religion? Is it something gained as a birthright, at a baptism, a result of devotional church attendance or even race? A case in Utah over peyote use has unearthed such questions, and the discussion seems to be just getting started.

Peyote, a small cactus whose button like tops can cause hallucinations when eaten, is considered a sacrament and a deity in American Indian religion, and the American Indian Religious Freedom Act was designed to make a legal exemption for its use in religious ceremonies by Indians who are members of tribes.

But a unanimous ruling this summer by the Utah Supreme Court allowed members of the Native American Church who are nontribal members to use peyote as well. The court ordered the case remanded to a lower court for reconsideration, but the state is considering an appeal to the United States Supreme Court.

''The First Amendment protects the rights of each person to worship according to their own beliefs,'' said Kathryn Collard, a civil rights lawyer who represented James Mooney, the defendant in the case.