Thought for the Lord's Day -- 38

...what the Mediator was to accomplish was no common thing. His task was so to restore us to God's grace as to make of the children of men, children of God; of the heirs of Gehenna, heirs of the Heavenly Kingdom. Who could have done this had not the selfsame Son of God become the Son of man, and had not so taken what was ours as to impart what was his to us, and to make what was his by nature ours by grace? Therefore, relying on this pledge, we trust that we are sons of God, for God’s natural Son fashioned for himself a body from our body, flesh from our flesh, bones from our bones, that he might be one with us. Ungrudgingly he took our nature upon himself to impart to us what was his, and to become both Son of God and Son of man in common with us. Hence that holy brotherhood which he commends with his own lips when he says: "I am ascending to my Father and your Father, to my God and your God". In this way we are assured of the inheritance of the Heavenly Kingdom; for the only Son of God, to whom it wholly belongs, has adopted us as his brothers. "For if brothers, then also fellow heirs with him."

For the same reason it was also imperative that he who was, to become our Redeemer be true God and true man. It was his task to swallow up death. Who but the Life could do this? It was his task to conquer sin. Who but very Righteousness could do this? It was his task to rout the powers of world and air. Who but a power higher than world and air could do this? Now where does life or righteousness, or lordship and authority of heaven lie but with God alone? Therefore our most merciful God, when he willed that we be redeemed, made himself our Redeemer in the person of his only-begotten Son.

- John Calvin