The Received Text and the Authorised Version attach the twenty-first verse to this exhortation by γὰρ ("for"): "For Him who knew no sin He made _to be_ sin on our behalf." The "for" is spurious, and though it is not inept the sentence gains greatly in impressiveness by its omission. The Apostle does not point out the connexion for us: in simply declaring the manner in which God reconciled the world to Himself--the process by which, the cost at which, He made peace--he leaves us to feel how vast is the boon which is offered to us in the Gospel, how tremendous the responsibility of rejecting it. To refuse "the reconciliation" is to contemn the death in which the Sinless One was made sin on our behalf.
This wonderful sentence is the inspired commentary on the statement of ver. 15--"One died for all." It takes us into the very heart of the Apostolic Gospel. Just because it does so, it has always been felt to be of critical importance, alike by those who welcome and by those who reject it; it condenses and concentrates in itself the attraction of Christ and the offence of Christ. It is a counsel of despair to evade it. It is not the puzzle of the New Testament, but the ultimate solution of all puzzles; it is not an irrational quantity that has to be eliminated or explained away, but the key-stone of the whole system of apostolic thought. It is not a blank obscurity in revelation, a spot of impenetrable blackness; it is the focus in which the reconciling love of God burns with the purest and intensest flame; it is the fountain light of all day, the master light of all seeing, in the Christian revelation. Let us look at it more closely.
God, we must observe in the first place, is the subject. "All" is of him in the work of reconciliation, and this above all, that He made the Sinless One to be sin. I have read a book on the Atonement which quoted this sentence three times, or rather misquoted it, never once recognising that an action of God is involved. But without this, there is no coherence in the Apostle's thoughts at all. Without this, there would be no explanation of reconciliation as God's work. God reconciled the world to Himself--made peace into which the world might enter--in making Christ sin on its behalf. What precisely this means we shall inquire further on; but it is essential to remember, whatever it mean, that God is the doer of it.
Observe next the description of Christ--"Him that knew no sin." The Greek negative (μὴ), as Schmiedel remarks, implies that this is regarded as the verdict of some one else than the writer. It was Christ's own verdict upon Himself. He whose words search our very hearts, and bring to light unsuspected seeds of badness, never Himself betrays the faintest consciousness of guilt. He challenges His enemies directly: "Which of you convinceth Me of sin?" It is the verdict of all sincere human souls, as uttered by the soldier who watched His cross--"Truly this was a righteous man." It is the verdict even of the great enemy who assailed Him again and again, and found nothing in Him, and whose agents recognised Him as the Holy One of God. Above all, it is the verdict of God. He was the beloved Son, in whom the Father was well pleased. For three-and-thirty years, in daily contact with the world and its sins, Christ lived and yet knew no sin. To His will and conscience it was a foreign thing. What infinite worth that sinless life possessed in God's sight! When He looked down to earth it was the one absolutely precious thing. Filled full of righteousness, absolutely well-pleasing in His eyes, it was worth more to God than all the world beside.