Let us learn, therefore, in every temptation to transfer sin, death, the curse, and all the evils that oppress us from ourselves to Christ, and, on the other hand, to transfer righteousness, life, and blessing from Him to us. For He does in fact bear all our evils, because God the Father, as Isaiah says (53:6), “has laid the iniquity of us all on Him.” And He willingly took them upon Himself. For He was not guilty; but He did this in order to do the Father’s will, by which we would be sanctified eternally.
This is the indescribable and infinite mercy of God which Paul would like to spread abroad with an enthusiastic and generous flow of words; but the human heart is too limited to comprehend, much less to describe, the great depths and burning passion of divine love toward us. Indeed, the very greatness of divine mercy produces not only difficulty in believing but incredulity. Not only do I hear that God Almighty, the Creator of all, is good and merciful; but I hear that the Supreme Majesty cared so much for me, a condemned sinner and a child of wrath (Eph. 2:3) and of eternal death, that He did not spare His own Son, but gave Him up into a most shameful death (Rom. 8:32), in order that He might hang in the midst of thieves and become sin and a curse for me, the sinner and accursed one, and in order that I might be made righteous, blessed, and a son and heir of God. Who can adequately proclaim this goodness of God? Not even all the angels. Therefore Holy Scripture speaks about other things than a political, philosophical, or even a Mosaic book; it speaks about the indescribable and utterly divine gifts that surpass not only all human and angelic understanding (Phil. 4:7) but everything else as well.
Luther’s Works, volume 26 (292-293)