What’s the purpose of God’s law? If we are saved by grace and through faith, what’s the point of the law? If Christ came to fulfill the law, does this mean God’s law no longer applies to us since Christ accomplished it for us?
By studying Romans 3:19-31, we can see four purposes in the Bible for God’s law.
1. The Purpose of God’s Law Is to Make Us Conscience of Sin
One of the primary purposes of the law is to expose sin. The law is like a mirror to show us if our behavior is looking like God or not. Without a mirror, you often won’t know what you really look like. And without the law, we often do not know if we are pleasing or displeasing God.
Now we know that whatever the law says it speaks to those who are under the law, so that every mouth may be stopped, and the whole world may be held accountable to God. For by works of the law no human being will be justified in his sight, since through the law comes knowledge of sin.” (Romans 3:19-20)
What then shall we say? That the law is sin? By no means! Yet if it had not been for the law, I would not have known sin.” (Romans 7:7)
Why then the law? It was added because of transgressions…” (Galatians 3:19)
As the IVP Commentary explains, “A transgression is the violation of a standard. The law provides the objective standard by which the violations are measured. In order for sinners to know how sinful they really are, how far they deviate from God’s standards, God gave the law. Before the law was given, there was sin (see Rom 5:13). But after the law was given, sin could be clearly specified and measured (see Rom 3:20; 4:15; 7:7). Each act or attitude could then be labeled as a transgression of this or that commandment of the law.”
With all the said, one common mistake is to then assume God’s purpose of the law was simply to show how futile man’s efforts are and thus need grace. John Piper explains:
Now I know that hardly anyone says that God saved people differently in the OT than he does today. But many Bible teachers say (or imply) that the law of Moses offers a way of salvation different than the way offered in the gospel. That is, virtually everyone agrees that anybody that was justified in the OT was justified by grace through faith; it was a gift of God. But many will still say that the law did not call men to be justified this way, it called them to earn God’s blessings through works, and in doing this it showed men their total inability and drove them to the Savior.
In other words, many Bible teachers will argue that the Mosaic covenant (made with Israel at Mount Sinai) is fundamentally different from the covenant with Abraham (made earlier) and the New Covenant (established at Calvary) under which we live. The difference, they say, is this: in the Abrahamic covenant and New Covenant salvation is promised freely to be received by faith apart from works of law. But under the Mosaic covenant salvation (or God’s blessing) is not offered freely to faith, but instead is offered as a reward for the works of the law. Since only perfect works could merit salvation from a perfectly holy God and nobody can achieve that, the law simply makes us aware of our sin and misery and pronounces our condemnation. This is probably the most popular view of the Mosaic law in the church today, and it is wrong. It makes a legalistic Pharisee out of Moses, turns the Torah into the very heresy Paul condemned at Galatia, and (worst of all) it makes God into his own enemy, commanding that people try to merit his blessing (and thus exalt themselves) instead of resting in his all sufficient mercy (and thus exalt him).”
Of course without God’s grace, we cannot please and obey him. But the law was never given as an alternative option for salvation opposed to the way of grace. The Old Testament does not offer a way of salvation based on works compared to the New Testament that offers a way of salvation based on faith and grace. Although the Israelites made a “works theology” out of God’s law, this was never his purpose for it. From the beginning, God’s purpose for his law was to point to the way of salvation through faith.
2. The Purpose of God’s Law Is to Testify to the Righteousness that Comes Through Faith
Romans 3:21-22 says, “But now the righteousness of God has been manifested apart from the law, although the Law and the Prophets bear witness to it— 22 the righteousness of God through faith in Jesus Christ for all who believe.”
So how does God’s law point us to the righteousness of God that comes through faith in Jesus? One way the law accomplishes this purpose is that obedience is the byproduct of faith. Therefore when God’s law calls us to be obedient, it is really calling us to have faith in God. When we read through Hebrews 11, we see a list of incredible saints who did amazing acts of obedience for God. But through the whole passage, you see this phrase, “By faith.” By faith Abraham, Moses, David, Rahab, and all the others obeyed God. Hebrews 11:6 states, “And without faith it is impossible to please him, for whoever would draw near to God must believe that he exists and that he rewards those who seek him.”
Romans 9:30-32, “What shall we say, then? That Gentiles who did not pursue righteousness have attained it, that is, a righteousness that is by faith;31 but that Israel who pursued a law that would lead to righteousness did not succeed in reaching that law. 32 Why? Because they did not pursue it [the law] by faith, but as if it were based on works.”
The Jews turned the law into a checklist for salvation. If you can check all the boxes, you will be saved, they reasoned. Why else would God give us the law? But Romans 9:32 says Israel missed the point of the law because they did not pursue obeying the law “by faith, but as if it we based on works.” The law is based on faith, and thus to obey the law humans must be living from that same base – faith. Again, as John Piper explains:
Israel twisted the Mosaic law into legalism. That is, they severed it from its foundation of faith, failed to stress dependence on the Spirit, and thus turned the commandments into a job description for how to earn the wages of salvation.”
People in the Old Testament and the New Testament are saved the same way, through faith in God. Galatians 3:24 says, “So then, the law was our guardian until Christ came, in order that we might be justified by faith.” The way of salvation has always been through faith. In the Old Testament, the law did not offer a different path of salvation (works) but guided people towards this truth that all, like Abraham (Galatians 3:6-9, James 2:20-24), are saved by faith alone.
3. The Purpose of God’s Law Is to Help Us Reflect God’s Image
Thus far we’ve covered Romans 3:19-22, which is all about explaining God’s purpose for the law. So when we get to Romans 3:23, we would expect it to continue this theme. It says, “for all have sinned and fall short of the glory of God.”
I think we would expect it to say that we fall short of “obeying God.” And we have, but in the process of disobeying God’s commands we have thus stopped glorifying God. What does it mean to glorify God? The glory of God is when the character of God is made knowable or visible. To glorify God is to manifest his image. We were made to glorify God, thus we were made in his image – as these two are basically the same.
The law is an expression of God’s character. God expresses his holiness in the law because he is holy. He expresses his love the law, commanding us to love him and others, because he is love. Everything we are told to do in the law will make us look like God when we do it. When we obey God’s law, we glorify him because we are reflecting him. When we don’t obey God, we are not glorifying him (Romans 2:23-24).
“Sin” means to “miss the mark.” What are missing the mark of? The glory of God, “for all of have sinned and fall short of the glory of God.” When we have faith in God, the law shows us what we are to do as we express that faith. All the law is summed up in love (Romans 13:8-10). Therefore Paul says in Galatians 5:6 (NIV), “For in Christ Jesus neither circumcision nor uncircumcision has any value. The only thing that counts is faith expressing itself through love.”
In other words, you don’t have to have faith to obey the letter of the law, therefore to be circumcised does not prove anything. But to obey the spirit of the law, which is to love, one must have faith. Therefore love is the mark of faith. And when we love, we reflect and thus glorify God.
Therefore to glorify God and reflect his image, we must love (fulfill the law), and to love (fulfill the law) we must have faith. The purpose of the law is to show us who to glorify God, which is through faith. Once again, Piper puts it like this:
So the first point in our theology of the law was that love fulfills the law. The second point was that love only comes out of faith in God’s promises. The third point, therefore, is that the law did not call for meritorious works, but for the obedience which flows from faith. If love is what the law aimed at, and only faith can love, then the law must teach faith. This is what has been overlooked so often.”
4. The Purpose of God’s Law Is to Be a Sign Marking Those Who Have Faith
When we read Romans 3:24-31, we see that from the beginning, God never intended to justify people through obedience to the law:
[for we] are justified by his grace as a gift, through the redemption that is in Christ Jesus, 25 whom God put forward as a propitiation by his blood, to be received by faith. This was to show God’s righteousness, because in his divine forbearance he had passed over former sins. 26 It was to show his righteousness at the present time, so that he might be just and the justifier of the one who has faith in Jesus. (Romans 3:24-26)
God didn’t save people in the Old Testament through their obedience to the law, rather he saved them through their faith expressed in their obedience to the law. He saved them through Jesus, looking past their sins towards the future atonement achieved in his Son, Jesus Christ.
So if the law never saved people, why was it given? Romans 4:9-11 says, “For we say that faith was counted to Abraham as righteousness. 10 How then was it counted to him? Was it before or after he had been circumcised? It was not after, but before he was circumcised. 11 He received the sign of circumcision as a seal of the righteousness that he had by faith while he was still uncircumcised.”
The law marks us for God. When we obey the law, it shows that we are his. Obeying the law does not save anyone, “For we hold that one is justified by faith apart from works of the law” (Romans 3:28).
So what comes of the law? Does it disappear for those who have faith. Never! Rather the law will be manifested in those who have faith, like the sign of circumcision given to Abraham who was counted righteous before being circumcised. Christians will obey the law not to be saved but because they already are saved. Romans 3:31 concludes, “Do we then overthrow the law by this faith? By no means! On the contrary, we uphold the law.”
So What’s the Purpose of God’s Law?
The purpose of God’s law is to reveal when we are not living by faith in God; it exposes our sins and make us realize we need God to save us by his grace and not by our own efforts.
The purpose of God’s law is to point us towards the way of righteousness that comes through faith in Jesus.
The purpose of God’s law is to show us how to glorify God through reflecting his image as we express our faith in love and obedience.
And the purpose of God’s law is to offer a sign of obedience on those who are saved by faith; for we are not saved by works but works show that we are already saved through faith.