One of the great mysteries of the Christian faith is how God could become a man. How does an infinite God take on finite human nature? What does this condescension tell us about God? What does it tell us about man? And how do we understand this God-man, who was “born of a woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons” (Galatians 4:4-5)?
Herman Bavinck has a ninety-page section called ‘The Person of Christ’ in the third volume of his Reformed Dogmatics that focuses solely on questions like these. Here I just want to quote for later reference one paragraph of that larger section which deals with the “essential distinction between the holiness of God and the holiness of Christ as a human being:”
The goodness or holiness of Christ according to his human nature is not a divine and original goodness but one that has been given, infused, and for that reason it must also–in the way of struggle and temptation–reveal, maintain, and confirm itself. Infused goodness does not rule out acquired goodness. The latter presupposes the former; good fruit grows only on a good tree, but the soundness of the tree still has to be shown in the soundness of the fruit. Similarly, Christ had to manifest his innate holiness through temptation and struggle; this struggle is not made redundant or vain by virtue of the inability to sin (non posse peccare). For although real temptation could not come to Jesus from within but only from without, he nevertheless possessed a human nature, which dreaded suffering and death. Thus, throughout his life, he was tempted in all sorts of ways–by Satan, his enemies, and even by his disciples (Matt 4:1-11; Mark 1:13; Luke 4:1-13; Matt. 12:29; Luke 11:22; Matt. 16:23; Mark 8:33). And in those temptation he was bound, fighting as he went, to remain faithful; the inability to sin (non posse peccare) was not a matter of coercion but ethical in nature and therefore had to be manifested in an ethical manner. (314-315)