In discussions against Calvinism it appears that little is remembered about the reasons for a Reformed anthropology. Part of this can also be seen in the Reformed understanding of the person and work of Jesus. Christ’s work is directly related to who he is. This Christmas we focus often on the birth of Christ and we can also take the time to be reminded of the significance of the Incarnation. The unique identity of Jesus determines the efficacy of his work. Why was it that God must be the one would be the Messiah? Calvin speaks in the Institutes (II, 12.3) that Jesus had to be God because only a Messiah who was simultaneously God and man could obey God on our behalf:
Accordingly, our Lord came forth as true man and took the person and name of Adam in order to take Adam’s place in obeying the Father, to present our flesh as the price of satisfaction to God’s righteous judgment, and, in the same flesh, to pay the penalty that we had deserved. In short, since neither as God alone could he feel death, nor as man alone could he overcome it, he coupled human nature with divine that to atone for sin he might submit the weakness of the one to death; and that, wrestling with death by the power of the other nature, he might win victory for us.
I think a good question for those who would reject the Reformed view of man after the Fall (Total Depravity), is to ask why was it that Christ had to be God. Otherwise, it seems at least possible that man could have attained salvation on his own apart from the perfect and complete work of Jesus. If we only needed the assistance of God then it seems that the sacrificial system in place could have worked ok. I understand this can start becoming a discussion of atonement theories very fast, however for the sake of the post and out of respect for the brevity I want to maintain, I am focussing on our doctrine of man.
Additionally, if we needed more than an existent grace (prevenient) it is possible at least to think that this could have existed apart from the person, work and death of Jesus. In the Reformed understanding of the person and work of Jesus we see not only his work as unique. We see the unity of his person with the work he would do. Apart from his personhood, his work would have been of no avail.