1. “Why then the law? It was added because of the transgressions”; “The law entered in alongside that the offense might abound” (Gal. 3:19; Rom. 5:20).
In God’s way of dealing with man, the law was added along the way because of man’s transgressions so that man’s offense might abound. The law was given to expose man’s transgressions and to cause man to know that he is sinful. Only in this way could man know his condition. God originally wanted—and still wants—to deal with man according to grace, but man did not know himself, so he did not see his need for the grace of God. When God saved the Israelites out of Egypt and brought them to Mount Sinai, He told them that He had brought them out of Egypt like an eagle, carrying them on its wings. This was a word of grace to let them know that He was full of grace toward them. If they had known their sinful condition, they would have received His grace and asked Him to continue dealing with them according to grace to bear all their responsibilities. But they did not know themselves, so they did not value or depend on God’s grace. Instead, they thought that they could carry out all that God commanded. They did not know themselves. They really thought that they could keep the commandments of God. Therefore, God’s attitude changed, and He gave the law to show that they could not keep His commandments.
God originally dealt with them according to grace. He was near and dear to them, carrying them like an eagle carries its young. But eventually He had to deal with them according to the law because they did not know themselves, and He came to them in smoke and flames that were awesome and terrible. God changed the way that He dealt with them because He wanted to expose their transgressions through the law; thus, they would know that they could not keep His commandments, because they were utterly fallen.
God did not give the law in order for the children of Israel to keep it; rather, He gave it because He knew that they would break it. In fact, when God was on Mount Sinai giving Moses the law, the children of Israel were at the foot of the mountain making a golden calf and worshipping idols, which broke the first three commandments. After Moses received the law from God and brought down two stone tablets, upon which the law was written, from the top of Mount Sinai, he saw that they were worshipping idols, and he broke the two tablets. Even while the law was being given and even before it was received by the children of Israel, they were trespassing and breaking it. God gave the law so that when it was broken their transgressions would be exposed. God added the law along the way to expose the transgressions of man. This is the purpose of the law. The law is like a mirror that shows people what they are really like so that they can know themselves. It does not make people evil; it reflects the evil that is already in them.
2. “Through the law is the clear knowledge of sin”; “I did not know sin except through the law” (Rom. 3:20; 7:7).
The law was added to expose man’s transgressions, so the function of the law is to give man the knowledge of sin. Without the law, man would not know what sin is, but with the law, man knows not only what sin is but also what sins he has committed. The law causes man to know sin and to know that he is a sinner.
3. “Condemnation”; “The law...speaks to those who are under the law, that every mouth may be stopped and all the world may fall under the judgment of God” (2 Cor. 3:9; Rom. 3:19; see also James 2:9).
Because the law causes man to know sin, it also condemns man. Since the law exposes man’s sin, it stops man’s mouth, making him unable to say anything, and it makes him submit to the judgment of God. With the law, man is willing to condemn himself and confess that he is a sinner who should receive God’s judgment.
4. “The law has become our child-conductor unto Christ that we might be justified out of faith” (Gal. 3:24).
God wanted to deal with man through grace in Christ. However, man did not look to the grace of God, because he did not know himself, and because he did not know that he was a sinner, he had no reason to believe in Christ. Therefore, God came in and gave the law to expose man’s transgressions so that man would know that he is a sinner and thus know himself. Since the law causes man to know that he is a sinner, it causes man to look to God for His grace and to believe in Christ. When a mirror shows a person that his face is dirty, it shows him his need to be cleansed. Thus, the law is our child-conductor unto Christ so that we might be justified out of faith. It causes us to look to God for His grace in Christ and to receive His salvation.