“Our preacher says the Law of Moses was not supposed to save anyone, that it was merely there for a while until Jesus came. If that is true, why did God give the Law of Moses at all, if it could not save anyone?”
“I do not nullify the grace of God, for if righteousness comes through the Law, then Christ died needlessly” (Galatians 2:21, New American Standard Bible)
“Is the Law then contrary to the promises of God? May it never be! For if a law had been given which was able to impart life, then righteousness would indeed have been based on law” (Galatians 3:21)
The apostle Paul would agree that the law could not save anyone. If the law could have saved, there was no point for Jesus to die. If God could have devised a law good enough to save man (that is, to impart righteousness) then Jesus did not need to die. But, as Paul pointed out, keeping the law can save no person. It could not save anyone.
So, why did God give the law? “Why the Law then? It was added because of transgressions, having been ordained through angels by the agency of a mediator, until the seed would come to whom the promise had been made” (Galatians 3:19).
First, Paul tells us the law was given because of transgression. Humanity needed a revealed standard for right and wrong and the law provided that. In other words, the law lets everyone know right from wrong and what God expected from His children. “Because by the works of the Law no flesh will be justified in His sight; for through the Law comes the knowledge of sin” (Romans 3:20). The law could point out a person’s sin, but the law could not remove sin.
Second, Paul tells us the law was put in place to point out our need for a savior. Since the law could not redeem anyone, it was given so we could look beyond ourselves to find a savior who could redeem us. “Therefore the Law has become our tutor to lead us to Christ, so that we may be justified by faith. But now that faith has come, we are no longer under a tutor” (Galatians 3:24, 25). The law was a guide to point us to Christ. Once we come into faith in Him, we no longer needed the guide to point us we have found what we needed.
The law served many functions, but it could not save. It could only remind us of our sinfulness. The law pointed us to the One who could save. That was its purpose. Once we find salvation through Jesus Christ, we no longer need the law.