The law of God helps us to know God, know ourselves, know our need, and know the life of peace and blessedness. It helps us to know God because it specifically reveals his character and his attributes, his holy will, what he’s like.
Paul tells us in Romans 1 that everyone knows right and wrong. But the law of God very specifically reveals to us God’s character and his own moral qualities. Morality is not arbitrary. God doesn’t tell us to do arbitrary things. God does not require us to do things that he is not prepared to do himself. So all morality is rooted in God’s character. And when we study the law, we see a display of God’s character.
God’s law also reveals to us ourselves, especially our sinful nature and our disobedience, our inclination to sin. For instance, when Jesus is talking to the rich young ruler, he says, “Go, sell what you possess, and give to the poor” (Matt. 19:21). And the rich young ruler essentially says to Jesus, “I can’t.” And he walks away sadly. Now what’s going on in that story? Is Jesus saying that we all have to give away all of our possessions? No. But in the case of the rich young ruler, Jesus is revealing to him by the law of God the specific nature of his own sin. What’s the first commandment? To have no other gods before me. And there, God in the flesh is saying to the rich young ruler, “What’s it going to be? Your money, your possessions, or me, God?” And the rich young ruler chooses something over God, before God.
That leads to the third thing that the law helps us with. It helps us to understand our need. When we know who God is, and we know that we don’t measure up to his morality and character, when we know who we are, and we know the sinful inclinations of our hearts, it presses us to Jesus, because we know that we have need of a Savior. And the Savior has fulfilled that law. He’s obeyed it perfectly, and he’s paid the penalty that is due to us for it. The law presses us to the Savior. It points us to the Savior. It takes us to the Savior.
Of course, the law also shows us the life of peace and blessedness. When we think about obedience, many of us immediately think, “Oh, do I have to? Do I have to do good works? Do I have to obey?” That wasn’t Jesus’s attitude toward God’s commands and God’s will. In fact, he frequently said to his disciples, “My food is to do the will of him who sent me” (John 4:34). In other words, he was saying that it was like spreading a seven-course banquet in front of him to be able to obey the law of God, the will of God. And once we’re redeemed, once we’ve trusted in Jesus Christ alone for salvation as he has offered in the gospel, the law not only is something that points us to Christ, but it also shows us how to live the life of peace and blessedness.
When God originally gave his commands to Adam and Eve in the garden, he gave those commands to them as blessings. They weren’t things upon which his love was contingent. He loved them and blessed them in the garden. And their obedience to the commands was the very sphere in which they enjoyed that blessedness. And when we are saved by Christ, when we are united to Christ, we are able to walk in a manner that is worthy of the gospel. We are to live in a manner that is like the Lord Jesus Christ. And he delighted in obeying God. And so the law of God shows us what that life of peace and blessedness is like. It shows us what it’s like to live a life worthy of the gospel once we’ve trusted in Jesus Christ.
These poor men think they can preach the Gospel without preaching the Law. I say, they must preach the Law, unless they do not mean to preach the Gospel. The Law entered that the offence might abound: proclaim it, I say, for this purpose among your ungodly congregations; lift up your voices like trumpets, and tell the people their transgressions, that you may glorify the more your honoured Master, in proclaiming the infinite riches and fulness of His great salvation. Preach the Law to those who believe, as finished, cancelled, dead for their salvation: point them to Immanuel as holding it in His bleeding hand, and saying to them, “If ye love me, keep my Commandments.”