Catechism lesson 31: The law (LD 34a)

The law of God, summarized in the Ten Commandments, show us the kind of life for which the Lord has made us. This is how people, led by the Holy Spirit, express their love for God.

LD 34 q&a 92.

What is the law of the LORD?

God spoke all these words:
I am the LORD your God,
who brought you out of the land of Egypt,
out of the house of slavery.

1. You shall have no other gods before me.

2. You shall not make for yourself a carved image or any likeness of anything that is in heaven above or that is in the earth beneath, or that is in the water under the earth.
You shall not bow down to them or serve them, for I, the LORD your God, am a jealous God, visiting the iniquity of the fathers on the children to the third and fourth generation of those who hate me, but showing steadfast love to thousands of those who love me and keep my commandments.

3. You shall not take the name of the LORD your God in vain, for the LORD will not hold him guiltless who takes his name in vain.

4. Remember the Sabbath day, to keep it holy. Six days you shall labour, and do all your work, but the seventh day is a Sabbath to the LORD your God. On it you shall not do any work, you, or your son, or your daughter, your male servant, or your female servant, or your livestock, or the sojourner who is within your gates.
For in six days the LORD made heaven and earth, the sea, and all that is in them, and rested on the seventh day. Therefore the LORD blessed the Sabbath day and made it holy.

5. Honour your father and your mother, that your days may be long in the land that the LORD your God is giving you.

6. You shall not murder.

7. You shall not commit adultery.

8. You shall not steal.

9. You shall not bear false witness against your neighbour.

10. You shall not covet your neighbour’s house; you shall not covet your neighbour’s wife, or his male servant, or his female servant, or his ox, or his donkey, or anything that is your neighbour’s.

LD 34 q&a 93.

How are these commandments divided?

Into two parts.

The first teaches us how to live in relation to God;
the second, what duties we owe our neighbour.

The purpose of the law

At this point, the Catechism has spoken of God’s law twice. In LD 2, it asked: From where do you know your sins and misery? and the answer was: From the law of God.

In what way does God’s law show us our sins and misery?

When we study the law of God, it is like a mirror, showing us the ugliness of our sins. This encourages us to look for a Saviour. This is sometimes called the first use of the law: to drive us to Jesus Christ, to ask him to forgive our sins and remove them from us.

A second use of the law benefits society: By punishing murder, theft, and so on, a government can reduce wickedness in a country. But keep in mind that the law of the land is often not in line with the law of God!

But the catechism focuses on the third use of the law. It pointed out that believers, through the Holy Spirit, grow in doing good works, out of thankfulness to God. Good works are only those which are done out of true faith, in accordance with the law of God, and to his glory (q&a 91). That is why we now ask the question: What is that law? So that we can learn to do truly good works, and praise God in that way.

When studying the law, we should ask ourselves: What does this teach me about showing thankfulness to the God who saved me?

The law of love

When someone asked Jesus: “What is the greatest commandment in the law?” Jesus did not pick one of the Ten Commandments. He quoted two other passages from the Old Testament.

Love the Lord your God with all your heart and with all your soul and with all your strength. (Deut. 6:5)

Do not seek revenge or bear a grudge against anyone among your people, but love your neighbour as yourself. (Lev. 19:18)

The keyword in these verses is love. Jesus taught us that all of God’s law is based on real, practical love. We show our love to God by worshipping him the way he instructed us. We show love to our “neighbour” by respecting and helping him or her.

Traditionally, we divide the Ten Commandments into two parts (or “tables”):

  1. Commandments 1-4 focus on our love for God.
  2. Commandments 5-10 focus on our love for others.

Just keep in mind that the two belong together: we love God by showing love for others, and we can only show true love for others if we do so out of love for God.

When studying the law, we should ask ourselves: What does this teach me about showing love to God and other people?

Jesus fulfilled the law

People often think about a “law” as things we must do, otherwise we may be punished. It is true that we have a duty to obey God’s commandments, and if we don’t, we are guilty and deserve punishment.

But the Bible teaches us clearly that sinful people cannot keep God’s law perfectly. Paul says that the way of “righteousness of the law” is a dead end. We can only be saved in the way of “righteousness of faith”, which means that we believe in Jesus as the one who did everything on our behalf.

Read Romans 4:13-16. In what way is Abraham “the father of all believers”?

In his life on earth, the Lord Jesus lived a perfect life. He truly loved God, his Father, and had deep love to anyone he met. In what he said and did, Jesus showed the beauty of the law. But it is also the other way around: the law of God shows us the beauty of Jesus Christ.

When studying the law, we should ask ourselves: What does this teach me about my Saviour, Jesus Christ?

The Law from Old Testament to New Testament

The Ten Commandments are part of the Law of Moses, which God gave to the Israelites when they were camped at Mt. Sinai. This law is presented in Exodus and Leviticus (and some in Numbers), and summarized in Deuteronomy. According to the Jews, the Law of Moses contains 613 commandments! This law has instructions about the sacrifices in the Tabernacle, about clean and unclean foods, about rituals for purification; laws about warfare and the treatment of slaved; principles of handling disputes in court and punishing criminals.

As Christians, we do not follow the Law of Moses. In Biblical language, we are not “under the law”.

Read Galatians 3:23-25. What was the role of the law? What changed when Jesus came?

At the same time, Jesus said in his preaching (Mat 5:17-20): “I did not come to abolish [the Law] but to fulfill it.” He did not get rid of the law, but gave the law its complete meaning. For instance, the animal sacrifices that were brought in the Tabernacle and Temple pointed to Jesus’ sacrifice of himself on the cross. We no longer sacrifice animals because the ultimate sacrifice has been brought.

To help us understand this, it is useful to think of three aspects of the law.

  • The moral law teaches basic principles of what is right and wrong.
  • The civil law regulates the Israelite society in the Promised Land.
  • The ceremonial law regulates the sacrifices, food laws, and other religious ceremonies.

The moral law does not change, because God’s ideas of right and wrong do not change. The civil law and the ceremonial law were specifically for the Israelites, to show them in a picture-like way the truth about Jesus’ heavenly kingdom. As the New Testament church, we no longer follow these rules, although we can often learn from them.

The Ten Commandments (or Decalogue) summarize especially moral law. They apply to us, too. In LD 34-44, the Heidelberg Catechism will show the principles of right and wrong taught in each commandment. Jesus did the same thing, for instance when he said that “do not murder” also means that we may not hate people or call them names.

When studying the law, we should ask ourselves: What moral principle is taught in each commandments, and how do I put that in practice in my life?


  1. “As a Christian, I must obey God’s law.” Is this the truth? Is this the whole truth?
  2. In Jer. 31:33, God promised: “I will put my law in their minds and write it on their hearts.” In what way is God doing this today?
  3. In his summary of the law, Jesus said: “Love your neighbour as yourself.” Who is your “neighbour”?
  4. “Be perfect, as your Father in heaven is perfect,” Jesus said at the end of Matthew 6. What does this practically mean for how you live?
  5. Read Col. 2:16-17 and Heb. 10:1, 11-12. What does the Bible teach here about the Old Testament law?


All: Make sure that you know the Ten Commandments (at least in summary) in the correct order.

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