Suppose a woman is in deep, deep debt and has no means at her disposal to pay it off. Along comes an ultra wealthy prince charming. Out of grace and love, he decides to marry her. He covers her debt. But then he has a choice to make about how he will care for his bride. After canceling out her debt, will he fill up her account with his money? That is to say, will he transfer or impute his own funds into an account that bears her name? Or will he simply make his own account a joint account so it belongs to both of them?
In the former scenario, there is an imputation, a transfer. In the second scenario, the same final result is attained, but there is no imputation, strictly speaking. Rather, there is a real union, a marriage.
I would suggest the first picture (the imputation picture) is not necessarily wrong, though it could leave adherents exposed to the infamous “legal fiction” charge since the man could transfer money into the woman’s account without ever marrying her or even caring for her. It could become, as Wright has said, “a cold piece of business.”
The second picture (the union with Christ picture) seems more consistent with Paul’s language, and for that matter, with many of Calvin’s statements. It does not necessarily employ the “mechanism” of imputation to accomplish justification, but gets the same result. Just as one can get to four by adding three plus one or two plus two, or just as one can get home by traveling Route A or by Route B, so there may be more than one way to conceive of the doctrine of justification in a manner that preserves its fully gracious and forensic character.
For Calvin, the central motif of Pauline theology is not “imputation,” but union with Christ.
In a somewhat related note, I see that James White was scheduled to talk about N.T. Wright tonight on "The Dividing Line." I'm sad that I missed it, considering White's previous "stellar" work on the subject. I also noticed that the latest issue of The Reformed Baptist Theological Review (Note: they haven't updated the site yet) will feature a book review of Wright's What Saint Paul Really Said written by Tom Hicks, also known as "SBTS" on the Derek Webb Message Board. I hope he's improved his usage of quotes in context over the last few months. We shall see. But that's enough griping for tonight.