This should be a simple question, but it becomes complicated because the Bible uses the word “Law” in so many different ways.
The New Testament often uses “law” in reference to the first five books of the Bible (the “law and prophets”, Acts 24:14). “The Law” can also refer to the Ten Commandments, the ceremonial law connected with the sanctuary service, the Law of Moses which gave regulations to ancient Israel, the “law of sin and death” (Romans 8:2), the “law of the Spirit” (Romans 8:2) and the civil law of the state.
Some of these have definitely been canceled. For example, the ceremonial law, that had to do with sacrifices, rituals, and festivals, was a “shadow” of what God intended to accomplish through Christ. Now that the reality has come, the shadow is no longer needed (Hebrews 7:12).
The law of Moses consisted of regulations for Israel as an agricultural theocracy, and as such, many of the laws are not relevant now, although the principles they are based on are still valid and deserve attention.
Most of the discussion of whether Christians have to keep the law concern the 10 Commandments. The fact that they were written on stone with the finger of God implies their perpetuity. Indeed, Jesus said “I say to you, till heaven and earth pass away, one jot or one tittle will by no means pass from the law until all is fulfilled” (Matthew 5:18). The fact that heaven and earth are still with us (not to mention sin) shows that the law is still in effect. The apostle Paul said, “Do we then make void the law through faith? Certainly not! On the contrary, we establish the law” (Romans 3:31).
Although this seems clear, Paul says other things about the law that raise questions. He calls the law “the ministry of death, written and engraved on stones” (2 Corinthians 3:7). He says, “You are not under law, but under grace” (Romans 6:14). “We have been delivered from the law, having died to what we were held by, so that we should serve in the newness of the Spirit and not in the oldness of the letter” (Romns 7:6). “As many as are of the works of the law are under the curse… No one is justified by the law… The law is not of faith… Christ has redeemed us from the curse of the law” (Galatians 3:10-13).
It is no wonder that many Christians have concluded that the law no longer applies to Christians. However, no one would want to say that Christians are free to neglect their parents, kill, steal, commit adultery or worship other Gods. It is important to understand what Paul is actually teaching, keeping in mind what Peter said, “Our beloved brother Paul, according to the wisdom given to him, has written to you, as also in all his epistles, speaking in them of these things, in which are some things hard to understand” (2 Peter 3:15,16).
Paul in his letters tries to clarify the purpose of the law, because of the problem of legalism. A legalist is someone who attempts keep the law in order to gain salvation, and Paul teaches that this is impossible— “By the works of the law no flesh shall be justified” (Galatians 2:16). We can only be justified and saved by believing that Christ took upon Himself the penalty for our sins, that He died the death that we should have died, and that He rose from the dead so that we can live.
This is why Paul said, “Christ is the end of the law for righteousness to everyone who believes” (Romans 10:4). The law cannot make us righteous, and all our attempts to deserve eternal life by faithfully keeping the law are in vain.
But just because “Christ is the end of the law for righteousness” does not mean that He is the end of the law for unrighteousness. The law still has a valid role— “By the law is the knowledge of sin” (Romans 3:20). “I would not have known sin, except through the law” (Romans 7:7). “Before faith came, we were kept under guard by the law, kept for the faith which would afterward be revealed. Therefore the law was our tutor to bring us to Christ, that we might be justified by faith” (Galatians 3:23,24).
The law reveals our sin. It condemns and convicts us and leaves us helpless and hopeless. But then God comes to us in our hopelessness and brings us the hope of salvation in Christ. By faith we take hold of His promises, and He justifies us and He fills us with His Spirit.
Then through the Spirit we are able to keep the law, not for salvation, but as the result of being saved. “For what the law could not do in that it was weak through the flesh, God did by sending His own Son in the likeness of sinful flesh, on account of sin: He condemned sin in the flesh, that the righteous requirement of the law might be fulfilled in us who do not walk according to the flesh but according to the Spirit” (Romans 8:3,4).
So do Christians have to keep the law? Perhaps this is a misleading question. Christians do not have to keep the law in order to be saved. But if they have been born again and believe in Christ, they will want to keep the law and they will be able to keep the law. If we cannot or do not want to keep the law it shows that we still need “the law… our tutor to bring us to Christ, that we might be justified by faith”.