Can Mosaic Law Save Us?

Romans 7:7-13
P.G. Mathew | Sunday, September 20, 2009
Copyright © 2009, P.G. Mathew

What shall we say, then? Is the law sin? Certainly not! – Romans 7:7

Have you ever noticed that all sinners are happy as long as the Holy Spirit is not convicting them through God’s law? If you ask such people how they are doing, they will say they are doing just fine. Their marriages are working out splendidly. Their children are studying at top universities. They are doing well at their jobs and their retirement funds are growing. They have no health problems and expect to live long and happy lives. But the truth is, such people are dead men walking. They have no concern about their standing before a holy God.

The rich fool of Luke 12 thought everything was going well for him. But God said to him, “You fool! This very night your life will be demanded of you” (Luke 12:20). There was a time when Saul of Tarsus lived such a carefree, happy life. God was not convicting him of his sins by the application of God’s law, so he felt fine. He said that concerning the righteousness of the law, he was perfect (Phil. 3:6). He said, “I was advancing in Judaism beyond many Jews of my own age and was extremely zealous for the traditions of my fathers” (Gal. 1:14). But then he writes, “Apart from law, sin is dead. Once I was alive apart from law; but when the commandment came, sin sprang to life and I died” (Rom. 7:8-9).

In Romans 7:7-13, Paul is vindicating the Mosaic law because up to this point in his epistle he has said many negative things about it. He declared the law cannot justify (Rom. 3:20); the law cannot sanctify (Rom. 7:1-6); the law increases sin (Rom. 5:20; 7:5); that believers are not under law but under grace (Rom. 6:14); that believers have died to law in death of Christ to be united to Jesus Christ so that we can bring forth fruit to God (Rom. 7:4, 6); and that through the law comes knowledge of sin (Rom. 3:20). Paul said that the law cannot restrain or curb sin; in fact, it does the opposite.

Such negative teaching about God’s law could prompt a person, especially a first-century Jew, to ask, “What then are you saying? Is God’s law sin?” Paul responds, “Certainly not!” Then he goes on to demonstrate the relationship of law to sin and death. Here Paul the Christian is looking at his life before conversion. He is thinking back to the time when the Holy Spirit applied God’s law to his heart after his encounter with the risen Christ on the road to Damascus. He may especially be thinking of the three days when, as a blind man, he fasted and prayed in Judas’ house on Straight Street in the city of Damascus.

On the Damascus road Paul saw that he totally misunderstood the design and purpose of God’s law. He realized that it was false way of salvation. He began to see that God designed the law so that through its application, sin might become so utterly sinful and foul that man might turn to Christ alone for salvation.

The law was given to unmask sin so that it may be shown in its true color of utter deception, destruction, and foulness. When the Holy Spirit applies the law to a sinner and convicts him of sin, he cries out, “I am all unrighteousness. Have mercy upon me, a sinner! I am a wretch. I am blind. I am lost. I am dead.” Professor Leon Morris comments that God’s law is not given to boost our self-esteem but to bust it.1So Paul is speaking from the standpoint of a convinced Christian, telling us from his own experience what happens to any sinner who is confronted with the law. Only in the light of God’s law does one see sin as an offense against God himself.

The Nature and Function of God’s Moral Law

What, then, is the nature and function of God’s moral law? Paul was aware of the fact of sin but he was not aware of its real nature and power until the Holy Spirit convicted him through the law, cutting him to the heart especially by the tenth commandment: “Thou shalt not covet.”

Most first-century Jews thought that only outward deeds like adultery and murder were sin, not inward attitudes like lust and anger. But the tenth commandment says evil lust itself is sin, as Jesus explained: “You have heard that it was said, ‘Do not commit adultery.’ But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart” (Matt. 5:27-28).

1. The law shows that we commit sin by transgressing God’s law.

When we have an evil desire for things belonging to another or things that are evil, we are transgressing the tenth commandment. We are sinning in our heart against God, and God knows our heart. This evil lust shows that our rebellion is against God himself because it is saying that we are not content with what God ordained for us. Instead, we want to grasp and possess what is not given to us. We become greedy and self-focused, a perversion that is the opposite of love. Our lack of contentment in God is the very heart of worldliness. We think that the things of the world will make us happier than God and his presence.

The tenth commandment destroyed Paul’s self-righteousness. He had to admit that he lusted sinfully countless times, though he never stole, murdered, or committed adultery. Once he thought he was blameless, but now he was convinced that he was blameful. The law revealed that he was a sinner who had committed a multitude of sins in his heart. Yet the law is not sin. The law reveals our sin nature and our many sins. It is a reagent that identifies the very presence of sin.

2. The law provokes sin, functioning as a catalyst so that we sin more.

Sin, through the law, creates a surge of rebellion in our hearts against God and his agents. Sin is enmity toward God; thus, a sinner is an enemy of God. Our sin nature twists God’s law so that we sin more. In this sense, God’s law stimulates sin.

When St. Augustine was sixteen years old, he and his friends went to his neighbor’s field at night, shook a pear tree, and stole all the pears. Later on, he analyzed why he stole. He was not hungry and he had lots of pears at home. In fact, he threw the stolen pears to the pigs. Why then did he steal the neighbor’s pears? He answers: “To enjoy the excitement and thrill of stealing, because God said, ‘Do not steal.'” The commandment “Do not steal” provokes stealing due to our sin nature. Sin twists God’s law and uses it for evil purposes.

We have seen this in our children. We say, “Do not do it,” and they want to do the forbidden action immediately and repeatedly. Then we direct them to do something, and they will not do it at all. Our sin nature is real and God’s law stimulates us to sin.

3. The law condemns sin (Rom. 7:9-11).

Paul says, “Once I was alive apart from law; but when the commandment came, sin sprang to life and I died.” (Rom. 7:9). It is like a person going to the doctor for a routine check-up, feeling very happy and seeming to have no problems. But all of a sudden the doctor says seriously: “You have terminal cancer.” That is the idea here.

Paul was happy outside of the law. He thought he had no problem at all. He thought he was righteous, pleasing God and keeping the law. He would say that he was doing just fine. But then the Great Physician confronted him with the law and revealed his serious problem. So he says, “When the law came, sin revived and I died.”

How many people are dead spiritually while they think they are fine! Yet God in his mercy tells us about our state through the gospel preaching. That is why many people will not go to a church where the whole Bible is preached because God uses the preaching of the law to bring conviction of sin.

At one time Paul, like the Pharisee and the rich young ruler of Luke 18, thought he was living a righteous life. He had no need of a Savior or atonement; he was “perfect.” But the Holy Spirit through the law cut Paul’s heart and convicted him of his sin. No longer alive in his self-esteem, self-righteousness, and self-approbation, he died and became all unrighteousness. Once he felt very righteous, though he was killing Christians. Now he realized what a wretched sinner he was.

Listen to Paul’s evaluation of himself when the Holy Spirit came upon him:

I thank Christ Jesus our Lord, who has given me strength, that he considered me faithful, appointing me to his service. Even though I was once a blasphemer and a persecutor and a violent man, I was shown mercy because I acted in ignorance and unbelief. The grace of our Lord was poured out on me abundantly, along with the faith and love that are in Christ Jesus.

Here is a trustworthy saying that deserves full acceptance: Christ Jesus came into the world to save sinners-of whom I am the worst. But for that very reason I was shown mercy so that in me, the worst of sinners, Christ Jesus might display his unlimited patience as an example for those who would believe on him and receive eternal life. (1 Tim. 1:12-16)

The law, therefore, is the straightedge that shows how crooked our heart is. In Acts 2:37 we read, “When the people heard this, they were cut to the heart and said to Peter and the other apostles, ‘Brothers, what shall we do?'” Jesus himself declared, “When [the Holy Spirit] comes, he will convict the world of guilt in regard to sin and righteousness and judgment” (John 16:8). When Nathan confronted David, saying, “You are the man!” David confessed to Nathan, “I have sinned against the LORD” (2 Sam. 12:7, 13).

When God is not working in our hearts through his law and convicting us, we can be happy. Once Paul felt that way. But when the law came home to him, he died. The law condemned him and he cried out, “Have mercy upon me, a sinner!” The law was God’s way of bringing sin to a head before its power was broken by the stronger grace of God.

Once when Professor John Gerstner was preaching in a church, a sophisticated woman came up to him at the end of his sermon and showed him her index finger and thumb half an inch apart. She said, “You made me feel like this much.” Dr. Gerstner said, “That is much too much. It will take you to hell.” We must see how sinful we truly are.

4. The law strengthens sin.

“The sting of death is sin; the power of sin is the law. But thanks be to God, who gives us the victory through Jesus Christ our Lord,” (1 Cor. 15:56). The law cannot break the power of sin. A legalist who depends on the law to justify and sanctify him can only sin, because in a sinner, the law gives power to sin. Every time he hears, “Do not fornicate,” he wants to fornicate and he does so. We need the Holy Spirit and need to be born again to break the power of sin. The law gives power to sin. More dependence on law means more sin, which means more guilt and more condemnation. But thanks be to God who gives us the victory through Jesus Christ our Lord by his death and resurrection! Through Christ, therefore, we die to sin and law. Set free from sin and law, we are united to Christ, saved forever by his life. Only then, by the power of the Spirit, can we delight in God’s law and bring forth fruit to God.

5. The law points us to Christ.

Paul says, “Christ is the end of the law so that there may be righteousness for everyone who believes” (Rom. 10:4). Elsewhere, he declares, “What, then, was the purpose of the law? It was added [to define] transgressions until the Seed to whom the promise referred had come. The law was put into effect through angels by a mediator” (Gal. 3:19). He adds, “So the law was put in charge to lead us to Christ that we might be justified by faith” (Gal. 3:24). The law only condemns and kills us. It destroys our self-esteem and self-righteousness, that we may look to Christ to justify, sanctify, and glorify us through his death and resurrection. The law kills so that Christ may raise us up from the dead.

6. For God’s people, the law reveals God’s will so that we may do it.

Paul writes, “Let no debt remain outstanding, except the continuing debt to love one another, for he who loves his fellowman has fulfilled the law. The commandments, ‘Do not commit adultery,’ ‘Do not murder,’ ‘Do not steal,’ ‘Do not covet,’ and whatever other commandment there may be, are summed up in this one rule: ‘Love your neighbor as yourself.’ Love does no harm to its neighbor. Therefore love is the fulfillment of the law” (Rom. 13:8-10).

God does not use our subjectivism to define sin. We must measure ourselves in the light of the objective standard of God’s law. For a believer, the law tells us what pleases God so that we may do it by the power of the Holy Spirit. A believer is born again. He is given a new heart and a new nature, and is indwelt by the Holy Spirit. No longer hating God’s law, he delights in it and meditates on it. He does the law and glorifies God by doing all things to the glory of God.

Through the power of the love of God shed abroad in our hearts by the Holy Spirit, we fulfill the law. A sinner is lawless because sin is lawlessness, but a believer is lawful. He is not an anti-nomian; he is pro-nomian. Love fulfills the law. Jesus said, “If you love me, keep my commandments.”

7. The law was never intended to save us.

Paul refers to this common misunderstanding in verse 10: “I found that the very commandment that was ‘intended to bring life’ actually brought death” (quotation marks added). Note the phrase: “intended to bring life.” It was the understanding of Judaism that people could be justified through the law. But it was never given to save us. So Paul says, “Therefore no one will be declared righteous in his sight by observing the law; rather, through the law we become conscious of sin” (Rom. 3:20). Then he says, “The law was added so that the trespass might increase” (Rom. 5:20). He writes, “For what the law was powerless to do in that it was weakened by the sinful nature, God did by sending his own Son in the likeness of sinful man to be a sin offering. And so he condemned sin in sinful man” (Rom. 8:3). Again he writes, “Is the law, therefore, opposed to the promises of God? Absolutely not! For if a law had been given that could impart life, then righteousness would certainly have come by the law” (Gal. 3:21). The truth is, the law was not given to impart life.

The Nature and Function of Sin

Having discussed the nature and function of the law, let us now look at the nature and function of sin. All children of Adam are born with sin nature. We are born enemies of God; our very thoughts and imaginations are against God. Dead in trespasses and sins, we are ruled by Satan, the spirit who now works in the sons of disobedience. We can only sin every day of our lives.

When such a sinner is given law by parents, teachers, police, or pastors, the sin in him takes advantage of the law to produce many sins, even sins he had not thought about. (PGM) The sin that is resident in us uses law as a base of military operation within our souls. So Paul sinned much against God, especially in terms of the tenth commandment: Do not covet.

Sin is extremely powerful. Dr. Martyn Lloyd-Jones says that next to God, sin is the greatest power in the universe. Only the grace of God can defeat and conquer sin’s great power. In this epistle Paul speaks of sin as a king with great power and authority. He writes, “So that, just as sin reigned in death, so also grace might reign through righteousness to bring eternal life through Jesus Christ our Lord” (Rom. 5:21). In Romans 6 he exhorts, “Therefore do not let sin reign in your mortal body so that you obey its evil desires. . . . For sin shall not be your master, because you are not under law, but under grace. . . . Don’t you know that when you offer yourselves to someone to obey him as slaves, you are slaves to the one whom you obey-whether you are slaves to sin, which leads to death, or to obedience, which leads to righteousness? But thanks be to God that, though you used to be slaves to sin, you wholeheartedly obeyed the form of teaching to which you were entrusted” (Rom. 6:12, 14, 16-17).

We find this idea of the powerfulness of sin throughout the Bible. In Genesis 4:7 the Lord told Cain, “If you do what is right, will you not be accepted? But if you do not do what is right, sin is crouching at your door; it desires to have you, but you must master it.” Jeremiah declares, “The heart is deceitful above all things and beyond cure. Who can understand it?” (Jer. 17:9). And Jesus taught, “What comes out of a man is what makes him ‘unclean.’ For from within, out of men’s hearts, come evil thoughts, sexual immorality, theft, murder, adultery, greed, malice, deceit, lewdness, envy, slander, arrogance and folly. All these evils come from inside and make a man ‘unclean'” (Mark 7:20-23).

Not only is sin powerful, but it is also ever-active. There is no Sabbath-rest for sin. It works hard day and night, from the time we are very young to when we are very old. Sin works hard even when we worship. Sin is active because the devil is active. He goes about as a roaring lion, seeking to devour especially and if possible God’s elect. If you feel angry as you hear the gospel preached, sin is working in your heart. But if the Holy Spirit is working in your heart, you will say to the preacher, “Amen,” meaning, “What you are saying is the truth.”

Sin works in us through our own evil lust. Lust is the root; fornication is the fruit. Lust is the root; stealing is the fruit. Lust is the root; adultery is the fruit. Lust is the root; murder is the fruit. First there is attitude, then action. This is why we need a new heart and the Holy Spirit so we can love God and do his will. Eve lusted first and ate the forbidden fruit. Achan lusted and stole. Ahab lusted and took Naboth’s vineyard by killing him. David lusted and took Bathsheba. Amnon lusted and raped Tamar. Judas lusted and sold Jesus for thirty pieces of silver. Demas lusted and abandoned Paul and the gospel for this world. Lust is the root; the specific sin is the fruit.

Sin cannot be cured by education or political or economic or scientific progress. Modern man hates the word “sin.” He says that man is born good and is getting better all the time. Yet this highly educated and civilized man is responsible for killing millions of people in wars, and in our country alone we have killed fifty million unborn children through abortion since 1973. Sophisticated, educated, civilized, rich people can be wicked murderers. They can violate every commandment. They hate the Bible, the God of the Bible, and anyone who preaches the Bible. That is why they get angry at a minister who preaches the gospel. Their anger shows the hardness of the human heart. They do not like it when we speak about sin and how we should practice righteousness. Above all, they hate Jesus Christ. Such nice, civilized, sophisticated people hate the moral model given in the Bible. They love the medical model that came out of evolutionary hypothesis and naturalism. So they will not call people sinners but patients.

Sin uses the bait of pleasure and thrill. Sin is a good fisherman. It shows us pleasure but hides the death that results from sin. There is pleasure in sin and we sin because we want pleasure. The Hebrews writer recognized this aspect of sin when he said Moses “chose to be mistreated along with the people of God rather than to enjoy the pleasures of sin for a short time” (Heb. 11:25). How many people have been deceived by the thrill, the pleasure, the excitement of sin! But then they crash to the ground, having ruined their lives through sin.

Sin kills its victims. Paul writes, “So that, just as sin reigned in death, so also grace might reign through righteousness to bring eternal life through Jesus Christ our Lord” (Rom. 5:21). Sin reigns in death. The wages of sin is death. No one sends a person to hell; people work every day of their lives to go there, and they will go there.

Sin totally deceives man. In Genesis 3:4-5 we read, “‘You will not surely die,’ the serpent said to the woman. ‘For God knows that when you eat of it your eyes will be opened, and you will be like God, knowing good and evil.'” This was pure lie. Yet how many people have listened to such lie and sinned! Look at verse 13: “Then the LORD God said to the woman, ‘What is this you have done?’ The woman said, ‘The serpent deceived me, and I ate.'” Paul writes, “You were taught, with regard to your former way of life, to put off your old self, which is being corrupted by its deceitful desires” (Eph. 4:22). The Hebrews writer says, “But encourage one another daily as long as it is called Today so that none of you be hardened by sin’s deceitfulness” (Heb. 3:13). Paul also writes,

For the secret power of lawlessness is already at work; but the one who now holds it back will continue to do so till he is taken out of the way. And then the lawless one will be revealed, whom the Lord Jesus will overthrow with the breath of his mouth and destroy by the splendor of his coming. The coming of the lawless one will be in accordance with the work of Satan displayed in all kinds of counterfeit miracles, signs and wonders, and in every sort of evil that deceives those who are perishing. They perish because they refused to love the truth and so be saved. (2 Thess. 2:7-10)

The antichrist is called the lawless one. There are people who call themselves Christians, yet they live like the lawless one. Such people are not Christians. Deceived by sin and Satan, they will perish.

Sin deceives us in many ways, including the following:2

  1. Sin misuses the law. The law must be used lawfully. Paul says, “We know that the law is good if one uses it properly” (1 Tim. 1:8). The law cannot justify or sanctify us. It reveals sin to us, and if we are God’s people, it reveals God’s will so we can do it. But sin misuses the law by saying lust is permissible as long as one does not sin outwardly. It says that evil intentions are not sin and God does not judge evil desire.
  2. Sin comes and says, “Because you sinned once and broke the law, you are hopeless. You might as well keep on sinning. More sins make no difference.”
  3. Sin encourages antinomianism, which says that we should not be troubled when we sin because we are saved by grace from first to last. It says, “Once saved, always saved, so it does not matter whether we sin or not. In fact, we can bring greater glory to God by sinning more because where sin abounded, grace superabounds. More sin equals more grace equals more glory to God.” This is the message of modern evangelicalism. Dr. Lloyd-Jones says, “Antinomianism is one of the most blinding curses that have ever afflicted the life of the Church.”3 People want pastors to champion antinomianism.
  4. Sin deceives us by creating within us an antagonism to the law, saying God is against us. Sin says God does not want us to have fun; that is why he prohibits us from doing certain things. It says if God were for us, he would let us do what we want.
  5. Sin says God’s law is unreasonable, unjust, and impossible.
  6. Sin deceives us into thinking very highly of ourselves.
  7. Sin says God’s law is oppressive, keeping us from developing into a god without needing law. God does not like competition.
  8. Sin deceives about itself. Sin makes sin very attractive and pleasurable. Sin says, “If it feels good, do it. Express yourself.”
  9. Sin makes righteousness look drab and unattractive. It says an obedient son is a mere dullard; a rebellious son is a lively and exciting person.
  10. Sin deceives us into overlooking the terrible, eternal consequences it brings to our own bodies and souls and to those of our children and children’s children for generations to come. Do we think about such long-term effects when we sin? Sin results in terrible consequences, including the final consequence of hell itself. But sin says, “You shall not surely die.”
  11. Sin deceives us into thinking, “I have kept the law perfectly. I am perfect. My pastor, my parents, and others have no clue about my perfection. Why are they so upset about my behavior?”
  12. Sin promises life but gives death. It promises happiness but gives misery. Sin promises divinity but makes us a demon. Sin promises holiness but gives corruption.

Is the Law Sin?

Is God’s law sin? Paul explains the true nature of God’s law: “The law is holy, and the commandment is holy, righteous and good” (Rom. 7:12). God’s law is holy. It is the absolute antithesis of evil. God is holy; so his law is holy. It is also righteous. Sin tells us that the law’s demands are unjust and unfair. But the law’s demands are just. A criminal is put to death for his crime, not because of unjust law. Finally, God’s law is good. The law tells us that God alone is good and so his law is good and good for us. A good life is a life lived in conformity with the law of God. The life of Jesus was the good life. Law is not evil. It is not the cause of sin and death. Sin is the cause of sin and death.

What, then, is the divine design and intention of giving us the law? Paul explains that God gave the law so that sin may be unmasked (Rom. 7:13). The nature of sin is deception, so God uses his law to expose sin that it may be recognized for what it is-utterly foul. Sin is stench in the nostrils of God. It is destructive and can only send us to hell.

The law reveals sin as utterly sinful so that we will hate sin with all our being. Jesus exposed Satan when he said, “The thief comes to steal, kill, and destroy.” Sin comes to steal, kill, and destroy us. “But I have come,” Jesus said, “that you may have life and that more abundantly” (John 10:10). The devil is a liar and the father of all lies.


The law is not sin; rather, it reveals and unmasks sin. We must therefore preach the law so that the Holy Spirit may convict sinners of their sin that they may turn to Jesus. Jesus saves only sinners who are convinced of their utter sinfulness.

Examine yourself. What is your reaction to a holy God who is Judge? What is your reaction to the preaching of the cross? What is your reaction to the Lord Jesus Christ? What is your reaction to the Bible? Is it hatred or delight? The first sign of spirituality is to feel dead, unclean, and lost.

This doctrine of sin and law is absolutely essential to understanding the gospel. That is why we preach the whole Bible. We cannot merely say, “God forgives you” or “God saves you.” What does he forgive? From what does he save us? When we preach God’s law, the Holy Spirit convicts us of our sin that we may turn to Christ and be saved.

The law cannot justify or sanctify. We are saved from sin’s penalty, power, and pollution only by the blood of Jesus applied to us by Holy Spirit. Therefore, if you are looking for a church, choose one where God’s entire word-law and gospel-is fully preached. Avoid churches that preach antinomian forgiveness; it will only encourage sin.

May God help us to welcome light and the brightness of light of God’s word. Once we were in darkness but now we are light in the Lord. May we live as children of light!

1 Leon Morris, The Epistle to the Romans (Grand Rapids: Eerdmans, 1988), 282.

2 Most of these points are listed by D. Martyn Lloyd-Jones, Romans: The Law: Its Functions and Limits, 155-160, and James M. Boice, Romans, Vol. 2: The Reign of Grace, 744-745.

3 Lloyd-Jones, 156.