Imagine you are a medieval artist assigned to paint the Annunciation—the very moment when Mary first hears the news that she has been singled out by God to bear “the Son of the Most High,…the king over the House of Jacob for ever” (Luke 1:32–33). You must show Mary’s reaction as she humbly accepts this astonishing and auspicious mission. You must portray the angel Gabriel. You must represent God’s Spirit, and what is perhaps your most difficult task, you must illustrate the Spirit becoming flesh—that is, Mary being impregnated by the Holy Spirit. As if that weren’t enough, you must keep in mind the centuries-long theological discussion of this miraculous event, described only once in the New Testament, in the Gospel of Luke: