Shall we honor the beliefs of Fred Phelps then? Where do we draw the line? Freedom of religion also grants the freedom from having others' religions imposed upon oneself. Marriage is controlled by the state. No religion has, or should have, control over what constitutes a legal marriage. When marriage effects someones life in that it changes their standing with the government financially and in other ways, it's far out of the realm of religion and has nothing to do with religious beliefs. If it's wrong and invalid in the eyes of a god, so be it. But marriage in the eyes of the state is a far different thing. To continue with your example, some fundamentalist Islamic people feel that it's right and good to sacrifice themselves in suicide bombings for a cause they feel their religion supports. By your logic, suicide bombing should be legal in the United States given that it's an aspect of religion. If people want to have religious beliefs, fine. But no one's spiritual fantasies should ever deny legal rights to another.