I wanted to comment on the continuing discussion on Hahn and Horton but as the conversation has drifted toward the difference between Rome and Geneva on Justification, I thought I would create a new post.
Let me suggest that the primary doctrinal difference with regard to justification, and it is a large difference indeed, is whether we are justified because we are good (taking for granted that that the goodness is formed by the sanctifying grace of Christ) or whether we are good because we have been justified by the wholly gratuitous imputation of Christ’s righteousness. All parties agree that holiness matters. The question is whether our personal holiness is the root or the fruit of our justification. As the heart of the question is whether justification is wholly forensic and judicial… a matter of imputation or infusion of Christ’s righteousness.
In order for our Roman Catholic readers not to be completely befuddled by Protestant reactions to Trent, our readers have to understand that Protestants are used to thinking of the imputation of Christ’s perfect righteousness as the sole hope of our salvation as the gospel. Sanctification, the mortification of the flesh, putting to death the old man, and renewing our minds after the likeness of Christ matter much… but they are not the center of our hope (but rather like filthy rags in comparison to the depths of Christ’s righteousness for us).
To answer Kevin- the Reformed read the Sermon on the Mount in the way we read the whole of the law… at once a definition of the ethics of the Kingdom and a reflection of our ethical duty as well as a reminder of how far short our personal righteousness fall when considered against the perfect standard of God’s holy law. Therefore, the Sermon on the Mount both encourages us to a renewed commitment to keeping God’s law while at the same time driving us away from our feeble attempts to keep the law in order to find our perfect righteousness in the finished work of Christ.