The faith is based on the belief that the will of one God is progressively revealed through the prophets of the great religions. The founder, Baha'u'llah, established the religion in 19th-century Persia, now Iran, which consequently expelled him.

For ex-Baha'i Juan Cole, though, this year's feast will be anything but festive.

Cole, a professor of Middle East history at the University of Michigan, is among the nation's leading experts on the faith. Until last May, when he formally resigned from the movement, he had been a Baha'i for 25 years. Now, however, he counts himself among a small but influential group of past and present liberal Baha'is angry over what they say is the hijacking of the faith by a cadre of conservative leaders more interested in preserving their authority than the Baha'i principle of ''independent investigation of reality.''

That principle is among the core tenets of the Baha'i faith first articulated by its founder, the l9th-century Persian prophet known as Baha'u'llah (the Glory of God) and who is revered by the faithful as an incarnation of God akin to Jesus.

According to the critics, the National Spiritual Assembly (NSA), which oversees the American Baha'i movement, is dominated by a tight-knit group of authoritarian officials who keep the lid on free expression by threatening dissidents with excommunication and by manipulating the process by which NSA members are elected.