BURR RIDGE, Ill. � In his day job, Kersey H. Antia is a psychologist who specializes in panic disorders. In his private life, Mr. Antia dons a long white robe, slips a veil over his face and goes to work as a Zoroastrian priest, performing rituals passed down through a patrilineal chain of priests stretching back to ancient Persia.

Skip to next paragraph

Enlarge this Image

Sally Ryan for The New York Times

Zoroastrians gathered for an annual fire ceremony last month in Burr Ridge, Ill. A portrait of the Prophet Zarathustra is in the background.

Multimedia

Audio Slide Show: A Religion in Decline