Only Begotten Daughter - James Morrow

Rejoice! A new messiah has come, and her name is Julie. Born to Murray Katz, the solitary (and celibate) keeper of an abandoned lighthouse on the Jersey shore, our protagonist arrives on Earth boasting supernatural abilities evocative of her divine half-brother, Jesus. As a child, she revels in her talent for walking on water, resurrecting dead crabs, and treating fireflies as luminous alphabet blocks. But after she reaches adolescence, her life becomes as challenging and ambiguous as any mortal's. Not only is Julie Katz obliged to deal with a silver-tongued devil and self-righteous neo-Christian zealots, she must also figure out what sort of mission her mother - the female Supreme Being - has in mind for her.
At once outrageous and affirming, this Nebula Award finalist is a magnificent work of contemporary satire that holds a mirror up to human nature, astutely reflecting our species' failings, foibles, and often misguided affections.