The New Testament contains two genealogies of Jesus, one in the Gospel of Matthew and another in the Gospel of Luke. They differ from each other in several respects – a fact that has been puzzling theologians for a long time. This paper explores some of the similarities and differences in these lists and their social and theological functions. We may never know whether Jesus’ grandfather was called Jacob (Matthew) or Eli (Luke), but it is clear that theologically he was “Son of David, Son of Abraham” (Matthew) and “Son of God” (Luke) according to his father’s family line, and also Son of God directly through the virginal conception of Mary. In terms of ancient kinship rules, there is no conflict here.