Whereas obedience is the response to grace, grace is the consequence of law keeping. The merciful will be shown mercy (Matt. 5:7). In response to his children’s obedience, the Father gives yet more grace. The righteousness for which believers hope (Gal. 5:5) is no less a gift than that which has embraced them in the gospel (Rom. 1:17; 3:21). At the Final Judgment, those who obey the law will indeed be declared righteous (Rom. 2:13), not as a basis for forgiveness, but as the Father’s glad acceptance and approval of what they have done in response to grace (cf. 1 Cor. 4:5; Matt. 25:21; Jas. 2:14-26).
Knox Chamblin, Continuity and Discontinuity: Perspectives on the Relationship Between the Old and New Testaments by John A. Sproule & C. Samuel Storms, eds. Crossway, 1988, pp. 194-195.
Dr. Chamblin was my best professor at RTS. One of his many memorable lines was: “You are never more faithful to Calvin than when you critique what he said by the Bible.” Dr. Chamblin loved (and I assume loves) Calvin. I believe that the Great Reformer would deeply share this sentiment.