Did Christ really have awesome abs? Western art has frequently stumbled over the contradiction between the ascetic figure of Jesus of Nazareth and the iconography of Christ inspired by the heroic, Hellenistic ideal: Christ as beautiful, tall and broad-shouldered, God's wide receiver; blue-eyed, fair-haired, a straight aquiline nose, Christ as European prince.

Rembrandt van Rijn, in a career rich with artistic innovation, begged to differ. A new exhibition at Paris's Louvre...