Murray Katz, a celibate Jewish recluse living in southeastern New Jersey, discovers that his most recent sperm donation has fertilized an egg. He then steals an ectogenesis machine and cares for the developing fetus in his abandoned lighthouse on Brigantine Point. Nine months later the daughter of God is born—Julie Katz, immaculately conceived half sister to Jesus and modern-day deity. Raised by Murray and his lesbian partner Georgina Sparks, Julie discovers her divinity early. By the age of two she is walking on water. Shortly afterward, she restores a dead crab to life. Murray, haunted by visions, makes Julie promise to stop performing miracles to remain hidden from her enemies. However, he does allow her to breathe in water and to continue visiting Absecon Inlet, where she maintains her friendship with a sponge named Amanda.
Tormented by the lack of communication with her divine mother, Julie struggles to determine her purpose on earth. She meets Andrew Wyvern, a self-described “man of wealth and taste” who is actually the Devil. He tricks her into displaying her powers by healing Timothy, the blind son of fanatical Revelationist Billy Milk. Questioning the wisdom of direct intervention, Julie opts for miracles by writing an advice column called “Heaven Help Us” for a tabloid.
When this plan backfires, Julie joins Wyvern for a sojourn to Hell, where she meets her half brother, Jesus, and learns the truth about divinity. She returns to earth fifteen years later—without her divine powers—and finds herself in New Jerusalem, a fanatical society run by the Revelationists. Threatened by the underground Uncertainty movement—a religion based on her own advice columns—Julie is captured and crucified by the Revelationists, who want to trigger the redemption of New Jerusalem and the return of Christ. She is saved, however, by the divine intervention of Amanda the sponge.