Did Christ have two wills corresponding to his two natures (human & divine) or did he have one will uniting the two natures? This is the kind of question that sounds custom-made for theology eggheads. Most of us have given less thought to this question than we have to the enigma of God’s ability to create an immovable object or the number of angels that can occupy a minuscule space.
But how significant and relevant it is for us to affirm that Christ had two wills! Consider the depth this bit of theology would add to concepts like prayer, obedience, the work of redemption, and our sympathetic high priest:
Jesus had ordinary human desires, longings, preferences, and aspirations. Just as truly, he had human aversions. Under these influences he made decisions and pursued options in the same way as we do ourselves.
This is clearly indicated in the Scriptures, not least in the way they distinguish between the will of Jesus and the will of God. This appears in, for example, John 6:38, ‘I have come down from heaven not to do my will but to do the will of him who sent me.’ Such language presupposes . . . the logical possibility that Jesus’ natural preferences (based on personal self-interest) might not always coincide with the wishes of the Father. . . The Servant consults not his own interests but the interests of others (Phil 2:4). This climaxes in Gethsemane, where the dilemma becomes almost unbearably acute. At a very basic level, Jesus does not want this ‘cup’. His whole nature shrinks from it, and as he speaks to his Father he becomes acutely aware that there are two wills (and two ways): there is ‘my will’ and there is ‘thy will’. Nor did Jesus find it easy to be reconciled to the Father’s will. It literally terrified him, because here was the concentrated essence of the mysterium tremendum. It was eerie. It was overwhelming. It was uncanny. Jesus’ victory consisted not in merging his will with that of the Father or even in wanting specifically what the Father wanted. It came from choosing the Father’s will rather than, and even over against, his own. He willed what he did not want…
-Donald Macleod, The Person of Christ, 179-180.