Blog 59: 2.7.8 - 2.7.13
The pedagogic (and first) use of law is to "shut our mouths" (Rom. 3:19), not so as to lead us to utter despair (as is the case with the reprobate) but to lead us to Christ: "But in Christ his face shines, full of grace and gentleness, even upon us poor and unworthy sinners" (2.7.8). This is true not just for unbelievers as they first come to Christ but for believers too.
The second use of the law is as a civil code so that "hindered by fright or shame, they dare neither execute what they have conceived in their minds, nor openly breathe forth the rage of their lust" (2.7.10).
The third ("principal," "proper") use of law "finds its place among believers in whose hearts the Spirit of God already lives and reigns" (2.7.12). And because we can never keep it as it demands, this should not "frighten us away." We must see this life of ours in Christ as "a race" (1 Cor. 9:24-26), "when its course has been run, the Lord will grant us to attain that goal to which our efforts now press forward from afar" (2.7.13). Thus, in the Genevan Catechism, he asked, "What is the rule of life which [God] has given us?" and replied, "His law." And sometimes, even among believers, the law functions as whip: "The law is to the flesh like a whip to an idle and balky ass, to arouse it to work. Even for a spiritual man not yet free of the weight of the flesh the law remains a constant sting that will not let him stand still" (2.7.12).
Calvin has only just begun to expound on the law's function in the Christian life but already we sense the magnitude of what he is saying and he was to see detractors in his day as we see in our own.