You can count on John Owen to bring some light and clarity into a debate. The following lightly edited quote was sent in by a reader and is really helpful:

"That which we affirm is that our sins were so transferred on Christ as that thereby he became responsible to God and liable to punishment in the justice of God for them. He was perfectly innocent in himself; but took our guilt on him, or our liability to punishment for sin. He may be said to be the greatest debtor in the world, who never borrowed nor owed one farthing on his own account, if he became guarantor for the greatest debt of others . . .

In order to declare the righteousness of God in this setting forth of Christ to be a propitiation and to bear our iniquities, the guilt of our sins was transferred to him in an act of the righteous judgement of God accepting and evaluating him as the guilty person—as it is with a guarantor in every case . . .

If this be not so, I desire to know what is become of the guilt of the sins of believers. If it were not transferred onto Christ, it remains still upon themselves, or it is nothing. It will be said that guilt is taken away by the free pardon of sin. But if that were so, there was no need of punishment for it at all—for if punishment is not for guilt, it is not punishment."

This is from page 200 of volume 5 of Owen's "The Doctrine of Justification by Faith Through the Imputation of the Righteousness of Christ Explained, Confirmed and Vindicated." (!!)

My reader said slightly cheekily, "I love the way Puritans give the game away in the title to their books. At least you know where he would be coming from in a discussion with Bishop N. T. Wright without having to read his book!"