It would not have been right for the restoration of human nature to be left undone, and… it could not have been done unless man paid what was owing to God for sin. But the debt was so great that, while man alone owed it, only God could pay it, so that the same person must be both man and God. Thus it was necessary for God to take manhood into the unity of his Person, so that he who in his own nature ought to pay and could not, should be in a person who could…