For no one can ever be made right with God by doing what the law commands. The law simply shows us how sinful we are. Romans 3:20 NLT
Well then, if we emphasize faith, does this mean that we can forget about the law? Of course not! In fact, only when we have faith do we truly fulfill the law. Romans 3:31 NLT
Sin is no longer your master, for you no longer live under the requirements of the law. Instead, you live under the freedom of God’s grace. Romans 6:14 NLT
In the three passages quoted above, the Apostle Paul makes some very telling and very important points about the Law of God. First of all, he tells us that the Law was not given so that we could earn our way into a right relationship with God by keeping it. That was the mistaken idea of the Pharisees. No, the Law had three purposes: to teach the character of God; to teach the character he would like to see in us; to teach us that we cannot produce that character on our own.
But just because we cannot fulfill the Law on our own does not mean that we can forget about it, says Paul. Jesus said the same thing (Matt 5:17). Jesus expects us to keep the Law. It is God’s instruction manual for human flourishing. Moreover, he expects us not merely to keep the letter, but more than that, its underlying spirit. It is not enough not to commit adultery; don’t think adulterous thoughts. Paul says the same: we can fulfill the law – reproduce the character of God – by means of faith in Christ.
But how do we do it? That is Paul’s final point. We do not fulfill the Law by keeping a careful list of its requirements and matching that with a careful list of how we are keeping those requirements. That is to be under the law, and it won’t work because our selfish disposition will keep defeating us. But we can defeat sin, the Apostle tells us. We do it by grace (through faith). By faith we have died to ourselves and come alive to Christ. Now the Spirit of Christ graciously empowers us to live Christ’s life if we will surrender ourselves to his absolute control (see Rom 8:1-17). That is what the Instruction Manual was all about in the first place – God’s life in us. So faith does not undercut the Law; it actually establishes it.