"What is the beginning of happiness?/ It is to stop being so religious." These lines, from the 12th-century Sufi mystic poet Hafiz, were probably intended with a great deal of irony, seeing how Hafiz was reputed to have memorized the entire Koran 14 different ways. Happiness, he seems to be saying, is the cheap wine, while true mystical enlightenment is the next day's hangover: a woozy, achingly exact sense of the full heft and grief of things. In Jamie Carmichael's new coming-of-age play, Pilgrims, these lines are used to counterpoint the spiritual