The Revealer

Aside from the first use of the Law as a mirror and its second use as a restrainer, John Calvin points out the “third and principal use, which pertains more closely to the proper purpose of the law.” This use “finds its place among believers in whose hearts the Spirit of God already lives and reigns” (Institutes of the Christian Religion, 2.10.12). Calvin is speaking here of the Law’s use to show us the will of our Creator, its function to reveal what pleases Him.

The third use of the Law is closer to the Law’s proper purpose because it would reveal God’s perfect will even if mankind had never fallen into sin. The use of the Law as a mirror to show us our faults, increase our sin, and point us to Christ (Gal. 3:19–29) is necessary because we are in bondage to evil apart from Jesus. We only need the Law to restrain our evil because in the fall sin entered our world. Were we born with hearts inclined toward obedience, however, the Law would still be “a lamp” to our feet and “a light” to our path (Ps. 119:105).

Believers across the ages have looked to the Mosaic law, specifically the Ten Commandments, to define the holy life, although the entire Torah does have value for the Christian. Remember that our Savior pleased the Father by keeping His Law perfectly, by seeing the will of God as His “food” (John 4:34). If the imitation of Jesus makes us grow spiritually (1 Cor. 11:1), and if Jesus followed the commandments of His Father to please Him, then it follows that we will please God if we keep His Law. We cannot keep it perfectly, and we cannot make Him love us or accept us through our obedience. However, we can bring Him pleasure in doing good. Freed from the curse of the Law through the cross, we can now keep these holy statutes by the power of His Spirit (Rom. 8:1–4).

We use the term elliptical to define the Ten Commandments, meaning that they enjoin the opposite of that which they forbid and forbid the opposite of that which they enjoin. The Sermon on the Mount teaches us to read the Law in this way. For example, not only are we to keep from murdering, we are also to do what we can to preserve our neighbor’s life, which includes mortifying our own sinful anger lest it spin out of control into a murderous rage (Matt. 5:21–26).