In "Biblical Perspective" Gordon Snider writes:

The law that was twisted by sin to enslave man was from the beginning the righteous counsel of God. God's purpose then in condemning sin was first to establish that His original counsel was righteous. But the purpose of sending Christ was also that the law might be fulfilled in us. God wanted it to be seen that His original plan for man was pos-sible, and our lives are to be the proof of that. Seen in this way there is no conflict between law and grace.

Source: Studies in Romans: Adult Teacher's Insights, page 41.