We obey the commandments, therefore, not in order to merit God’s favor, but out of gratitude for his favor.

Don’t forget that the Ten Commandments were given to Israel after God delivered them from Egypt. The law was a response to redemption not a cause of it. We must never separate law from gospel. In one sense, the law shows us our sin and leads us to the gospel, but in another sense, the law ought to follow the gospel just as the giving of the Decalogue followed salvation from Egypt.

From time to time I make new entries into this continuing series called “Theological Primer.” The idea is to present big theological concepts in under 500 words. Today’s topic is as thorny as they come: the relationship between law and gospel.

The Heidelberg Catechism (1563) is largely composed of three elements: the Apostles’ Creed (Lord’s Day 7-22), the Ten Commandments (Lord’s Day 34-44), and the Lord’s Prayer (Lord’s Day 45-52). It’s worth noting, as many have, that this most beloved of all Catechisms includes its exposition of the Law in the section on gratitude, not in the section on guilt. This choice reflects the widespread Reformation belief in the so-called third use of the law.

(1) The law is given to restrain wickedness.

(2) The law shows us our guilt and leads us to Christ.

(3) The “third and principal use” of the law (as Calvin put it) is as an instrument to learn God’s will. The law doesn’t just show us our sin so we might be drawn to Christ; it shows us how to live as those who belong to Christ.

In one sense Christians are no longer under the law. We are under grace (Rom. 6:14). We have been released from the law (Rom. 7:6) and its tutelage (Gal. 3). On the other hand, having been justified by faith, we uphold the law (Rom. 3:31). Even Christ recoiled at the idea of coming to abolish the law and the prophets (Matt. 5:17). Christians are free from the law in the sense that we are not under the curse of the law–Christ is the end of the law for righteousness to everyone who believes (Rom. 10:4)–nor is the law a nationalized covenant for us like it was for Israel.

But the law in general, and the Ten Commandments in particular, still give us a blueprint for how we ought to live. The Ten Commandments were central to the ethics of the New Testament. Jesus repeated most of the second table of the law to the rich young man (Mark 10:17-22). The Apostle Paul repeated them too (Rom. 13:8-10), and used them as the basis for his moral instruction to Timothy (1 Tim. 1:8-11). There can be no doubt that the commandments, even under the new covenant, are holy and righteous and good (Rom. 7:12).

We obey the commandments, therefore, not in order to merit God’s favor, but out of gratitude for his favor.

Don’t forget that the Ten Commandments were given to Israel after God delivered them from Egypt. The law was a response to redemption not a cause of it. We must never separate law from gospel. In one sense, the law shows us our sin and leads us to the gospel, but in another sense, the law ought to follow the gospel just as the giving of the Decalogue followed salvation from Egypt. Likewise, Ephesians 2 first explains salvation by grace and then instructs us to walk in the good deeds prepared for us (v. 10). Romans first explains justification and election, and then tells us how to live in response to these mercies (Rom. 12:1).

In short, we obey the law in gratitude for the gospel. As Louis Berkhof observed, we distinguish between the law and the gospel, but always as “the two parts of the Word of God as a means of grace” (Systematic Theology, 612).

Kevin De Young has been the Senior Pastor at University Reformed Church (RCA) in East Lansing, Michigan, right across the street from Michigan State University, since 2004.  Kevin blogs at the Gospel Coalition and this article is reprinted with his permission.