In the NT, “law” is sometimes used to mean customs, sometimes natural principles, sometimes the whole of God’s revelation, and sometimes it means the Mosaic code which regulated the lifestyle of Israel. In Paul’s letters to the Romans and the Galatians he examines the Mosaic law and makes many startling statements. According to the NT, the law of Moses was temporary, limited in its purpose, and actually stimulated human beings to sin. The law of Moses condemns rather than helps mankind to find righteousness!
Theologians distinguish three functions of the Mosaic law. (1) Law reveal God. Seeing the “holy, righteous, and good” standards which God has communicated, we understand more of the moral character of the God who gave it. And we receive a partial explanation of righteousness. (2) Law convicts of sin. When man hears God’s law, the old nature is even stimulated to acts of sin! The great contrast between what law says is good and what human beings do is underlined, and thus mankind stands silent in court, condemned before God. (3) Law is a guide for the believer. It is this “third function of law” which theologians debate. Are we to be guided by law today? Do we seek to please God by acting on his commandments or is there some other way?
Paul in Romans and Galatians rejects this “third function” concept. He teaches that law always relates to the old nature. In fact law energizes or stirs up that nature. No wonder 1 Corinthians 15:56 says that “the power of sin is the law!”
What does the Bible put in place of law as the Christian’s guide to holy living? Jesus said it when he promised his disciples the Spirit: “he will guide you into all truth” (John 16:13). This is the reality Paul turns to in Romans and Galatians. It is the Holy Spirit who energizes the life of God within: it is those who live “in accordance with the Spirit” in whose lives the righteous requirements of the law are fully met (Rom. 8:5).
But when he, the Spirit of truth, comes, he will guide you into all the truth. He will not speak on his own; he will speak only what he hears, and he will tell you what is yet to come. John 16:13
Those who live according to the flesh have their minds set on what the flesh desires; but those who live in accordance with the Spirit have their minds set on what the Spirit desires. Romans 8:5
The saints of both testaments trusted God and relied on him rather than on their own efforts. But all too many have misunderstood the dynamics of personal relationship with God. Man does not need to behave righteously: man needs to be righteous (see Righteousness). It is not the law written in stone but the law he is writing on our hearts with which God is concerned (2 Cor. 3). Law may tell us how to behave. But only God’s Spirit can make the loving kind of life law describes a spontaneous expression of a personality which God is reshaping from within.
For study: Romans 6-8; Galatians 5; Hebrews 8; 2 Corinthians 3.