Medieval Christians and Jews agreed that the doctrine of a redeeming Messiah was omnipresent throughout the Hebrew Bible. As we have seen, Christians and Jews could and did argue vigorously as to whether the Messiah acknowledged by Christians appeared at the time predicted for messianic advent and as to whether Jesus of Nazareth exhibited messianic characteristics, for example the qualities associated with Isaiah's Servant of the Lord. Christians further contended that the biblical messianic figure was predicted to be both human and divine and that Jesus of Nazareth was in fact both human and divine. Here, however, Jews disagreed vehemently with Christians on the conceptualization itself. Medieval Jews were strongly committed to the position that such a combination is unthinkable. They insisted that God alone is divine and that the promised Messiah was intended by God to be thoroughly human. Once again, as with the issue of divine rejection of the Jews, our Jewish polemicists defended against Christian thrusts and took to the offensive as well.

We shall soon see Christian efforts to prove that the doctrine of Incarnation was reasonable, indeed that compelling circumstances forced God to become incarnate. In addition to argumentation from reason, Christians contended that this truth is obvious in numerous biblical verses, and it is with this line of argumentation that we shall begin. Since we have examined closely the books of Daniel and Isaiah, we might note that Christian thinkers drew evidence for Jesus' divine nature from both texts.