The Law of God is man’s friend if he is in Christ. It is not his master, and it cannot condemn him. But it does help as a good friend does. It directs him away from the things of the flesh because when he lives this way he is hostile to God (Romans 8:7). In that state he will not submit to God’s Law. Instead the Law informs him of God’s definitions of what is good and evil. And it helps him to see just how love for God in Christ should be expressed.
The law sends us to the Gospel that we may be justified; and the Gospel sends us to the law again to inquire what is our duty as those who are justified. 
Recently the topic of the relationship between the Law and the Christian has been occupying a significant amount of my thoughts. That is for two main reasons: 1. I read Charles Leiter’s book The Law of Christ; and, 2. I am preaching through the book of Romans. Why have these things made me consider God’s Law?
First, Charles Leiter’s book is antinomian. That does not mean he is unconcerned with holiness or urging Christians to a righteous life. It is antinomian because Leiter dismisses God’s Law. His basic premise is that the Law (ceremonial, civil, and moral) is abrogated and serves only as an example for the new covenant Christian, unless explicitly repeated in the New Testament. To be renewed by the Holy Spirit, argues Leiter, means the heart is changed and there is a desire to imitate Christ. Therefore the Law is no longer needed. That book forced me to think about the abiding use of the Law from the perspective of someone who would remove it.
Second, preaching through Romans makes me think about the Law, but for a very different reason. Paul is constantly talking about the law. Romans has been divided into 433 verses. 51 of those, or 12% of the verses, mention the word “law”. Sixty-six of those 78 mentions are in the first seven chapters. Of those 51 verses which mention the Law, 41 appear in the first seven chapters. There are 186 verses in those chapters, which means that 22% of the verses in the first seven chapters of Romans use the word “law”. That is a major theme. But in this book, the Law is not being cancelled. Paul is helping the Christian think of the right use of the Law in his life. The Law cannot be used unto salvation, but salvation encourages a right use of the Law.
All of these things have caused me to be refreshed by the Biblical teaching that the free offer of the gospel does not negate the Law’s usefulness for the Christian. There are many Scriptural references to support this way of thinking:
John 14:15 “If you love me, you will keep my commandments.”
Romans 3:31 “Do we then overthrow the law by this faith? By no means! On the contrary, we uphold the law.”
Romans 8:7 “For the mind that is set on the flesh is hostile to God, for it does not submit to God’s law; indeed, it cannot.”
1 John 3:4 “Everyone who makes a practice of sinning also practices lawlessness; sin is lawlessness.”
Texts like these have formed the foundation for the protestant Christian’s belief in the abiding value of God’s Law. The universal nature of this acceptance can be seen in the theological documents that were formulated throughout the Protestant Reformation.
The Sixteenth Century
The Heidelberg Catechism was published in 1563, written primarily by Zacharias Ursinus. It quickly came to be viewed as the best summation of the teachings of reformed Christianity and continues to be used and loved in many Reformed denominations. In Q. 3, the catechism establishes the Law as a convicting agent: “From where do you know your sins and misery? From the law of God.” It is commonly accepted that the Law functions in this way, but the catechism has more to say. It also describes life after the new birth, when man is renewed by the Holy Spirit. This life is the forgiven life, when man is pardoned for sin and declared righteous by faith in Christ. Describing that time, Q. 90 says, “What is the coming to life of the new nature? It is a heartfelt joy in God through Christ, and a love and delight to live according to the will of God in all good works.” And so as to make no mistake about the nature of these good works, the Catechism gives a clarifying definition in Q. 91: “But what are good works? Only those which are done out of true faith, in accordance with the law of God, and to his glory, and not those based on our own opinion or on precepts of men (Italics mine).” In the Heidelberg, the doing of good works which is part of the coming to life of the new nature, is defined by living in obedience to God’s Law.