The New Age Movement is in a class by itself. Unlike most formal religions, it has no holy text, central organization, membership, formal clergy, geographic center, dogma, creed, etc. They often use mutually exclusive definitions for some of their terms. The New Age is in fact a free-flowing spiritual movement; a network of believers and practitioners who share somewhat similar beliefs and practices, which they add on to whichever formal religion that they follow. Their book publishers take the place of a central organization; seminars, conventions, books and informal groups replace of sermons and religious services.