Galatians 3:18-20

If the law could give us Abraham’s blessing, then the promise would not be necessary. But that is not possible, because God freely gave his blessings to Abraham through the promise he had made. So what was the law for? It was given to show that the wrong things people do are against God’s will. And it continued until the special descendant, who had been promised, came. The law was given through angels who used Moses for a mediator to give the law to people. But a mediator is not needed when there is only one side, and God is only one.