By the Law Is the Knowledge of Sin

As a christian, the apostle Paul continued to be interested in the Law of God—the same Law as he had studied and sought to live by as a Jewish Pharisee (Acts 26:5; Philippians 3:5). Those who wish to neglect God’s Law focus on the fact that the Lord Jesus Christ called him to be the “apostle of the Gentiles” (Acts 9:15; Romans 11:13; 1 Timothy 2:7; 2 Timothy 1:11). However, Paul has a lot to teach all Christians about the law of God, both in its use to bring people to Christ and its use in the to Christians for instruction in godly living. And he has included his teachings in his epistles.

When he wrote about the “the law,” the apostle usually¹ meant that body of laws revealed by God and contained in the five books of Moses—which the Jews call the Torah (this word means the Law in Hebrew). He often, though not always, focused his reader’s attention upon the moral laws within the Law:² these comprise God’s own revealed, and precise, definition of what is righteous and what is sin—what is morally right and wrong.³ Indeed, whenever Paul preached or wrote about the quinteseentially Christian doctrines of sin, righteousness, judgment, justification, sanctification, holiness, godliness, etc.—all these have to do with God’s moral law.

Both Jews and Gentiles are held accountable by God to his moral law. The truth is as Paul teaches us: “Now we know that what things soever the law saith, it saith to them who are under the law: that every mouth may be stopped, and all the world may become guilty before God” (Romans 3:19).

The Jews were “under the law”—the Law of Moses, which we also know as the Old Testament (Old Covenant). But here Paul declares that the scope of the moral code of the Torah includes “all the world,”⁴ both Jew and Gentile. This should not be an unacceptable assetion to us, because the same moral law is part of the basic innate knowledge that all mankind has in the human conscience, even where it is suppressed and rejected (see Romans 1:18; see also Romans 1:28-32; 2:1-3, 14-15).

The apostle gives testimony of his own experience of the work of the Holy Spirit in the soul—in applying God’s moral law. He says, “I had not known sin, but by the law…For without the law sin was dead. For I was alive without the law once: but when the commandment came, sin revived, and I died. And the commandment, which was ordained to life, I found to be unto death. For sin, taking occasion by the commandment, deceived me, and by it slew me…sin, that it might appear sin, working death in me by that which is good; that sin by the commandment might become exceeding sinful” (Romans 7:7-13; the reader should find it useful to study the whole chapter). By “that which is good,” Paul clearly means that which is defined as good by the Law of God (elsewhere he also says that the law itself is good; see Romans 7:12, 16; 1 Timothy 1:8).

Paul refers back to his own pre-regenerate state as being “alive without the law” (v.9). We need to understand what he means by this unexpected statement, that seems to be a contradiction but it is not. For although Paul⁵ had been a Pharisee of the Jews, yet he confesses that in those days he hadn’t applied that law so rigorously to his own soul as the Holy Spirit would do upon regenerating him. He thought he was alive and living quite well, for in his fallen nature (same as with all of us) Paul had rejected his predicament as guilty before God, whether as understood by the revealed law or by his conscience.

He describes the time when the Spirit reproved him of righteousness (John 16:8-10)⁶ as the time when “the commandment came” to him. His conscience was made tender through his regeneration—but at the same time the response of his fallen nature was an even greater rebellion against God; as he said, “sin revived, and I died” (v.9).

That is how man’s sinful nature manifests its enmity against God (Romans 8:7). When confronted by the moral law, we perversely strive to sin all the more! And through observing this devastating fact in his own case, Paul came to understand how sinful and spiritually dead his fallen nature really was.

Paul could not stop himself sinning (see Romans 7:15, 23). And now, by the reproving of the Holy Spirit, he was painfully aware that he was deliberately sinning against God and against his own renewed, tender conscience.

Paul’s pretense and sanctimonious pride was stripped away when “the commandment came” to him. Now he faced the fact that he was indeed a hell-deserving sinner; and he knew that could not help himself. And now his sins were all, as it were, awakened and lively within his heart.

His own sinfulness, by the convicting work of the Holy Spirit, now “appeared sin” to him—it had “become exceeding sinful” (Romans 7:13), in his own opinion.

And so Paul says about himself, “I died.” Here is where Saul the self-righteous Pharisee (or so he had thought) gave up all hope in himself. His eyes were now opened, and he could see his his spiritually dead, hopeless, lost, fallen nature for what it was.

He was made to understand that all his so-called righteousnesses were indeed as filthy rags in God’s eyes, and he began to truly hunger and thirst after that righteousness which is “without the law,” namely the righteousness of Christ (Isaiah 64:6; Matthew 5:6).

These heart-experiences of the apostle Paul, which he described in general terms without going into the details of his own particular sins, are the experiences of all the Lord’s people.

If the Holy Spirit applies the moral law of God to our hearts, so that we know in our own experience what Paul was talking about here, then it stops our mouths boasting about how good we are, and it slays our self-righteous pride. It shows us what we really are—how the righteous God sees us (unless we are saved).

We will no longer think of ourselves with pride for our moral goodness—because now we know the truth: “There is none righteous, no not one…” (Romans 3:10-18)—so, no, I am not righteous at all, and I cannot be good at all. For unless God has put new life into my soul, I am spiritually dead in my sins, and I remain a hell-deserving sinner.

The Holy Spirit shows us our awful predicament before the holy and just God. This is how we come to understand how burdened down we are with our sins.

Paul concludes that the lesson God’s law should teach us is this: “Therefore by the deeds of the law there shall no flesh be justified in his [God’s] sight: for by the law is the knowledge of sin” (Romans 3:20).

But we have not finished learning the lesson of the law if we are left there.

Appendix

The Heidelberg Catechism, Question and Answer 3.

How knowest thou thy mystery?
Out of the law of God.

Zacharias Ursinus, Commentary on the Heidelberg Catechism, at Question 115.⁷

When we enquire concerning the use of the divine law, it is necessary that we should keep in view the differences of each part of the law [i.e. ceremonial, judicial, and moral laws]…

The uses of the moral law are different according to man’s fourfold state.

I. In nature uncorrupted, or not as yet depraved by sin, as our nature was before the fall, there are two principal uses of the divine law:

1. The entire and perfect conformity of man with God. The mind of man before the fall possessed a perfect knowledge of the law, which produced a conformity and correspondence of all the inclinations and actions with the will of God.
2. A good conscience, or a consciousness of the divine favor, and certain hope of eternal life. The law, according to the order of divine justice, promises life to those who render a perfect obedience to its requirements. “Which if a man do, he shall live in them” (Leviticus 18:5).

II. In nature corrupted, and not as yet renewed by the Holy Spirit, there are also two uses of the law:

3. The preservation of discipline and external propriety in the church and world. The law being engraven upon the minds and hearts of all men by God himself, and speaking by the voice of ministers and magistrates, curbs and restrains even the unregenerate, so that they shun those flagrant and open forms of wickedness, which are in opposition to the judgment of sound reason as it utters itself even in persons unrenewed by the Spirit of God, and which must be removed before regeneration. “When the Gentiles, which have not the law, do by nature, the things contained in the law, these, having not the law, are a law unto themselves; which shew the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the meanwhile accusing, or else excusing one another” (Romans 2:14-15).
4. The knowledge of sin of sin. The law accuses, convinces, and condemns all those who are not regenerated, because they are unrighteous before God, and subject to eternal condemnation. “We know that what things soever the law saith, it saith to them who are under the law, that every mouth may be stopped, and all the world may become guilty before God. Therefore by the deeds of the law, there shall no flesh be justified in his sight; for by the law is the knowledge of sin.” “I had not known sin, but by the law; for I had not known lust except the law had said, Thou shalt not covet” (Romans 3:19-20; 7:7). This use of the law, which consists in a knowledge of sin, and of the judgment of God against sin, produces in itself in the unregenerate hatred of God, and an increase of sin, and if they are reprobate it drives them into despair, as it is said, “The law worketh wrath.” “Sin taking occasion by the commandment, wrought in me all manner of concupiscence. For without the law sin was dead” (Romans 4:15; 7:8.) This knowledge of sin, however, is by an accident a preparation to conversion as it respects the elect, seeing that God by this means leads and constrains them to acknowledge their unrighteousness, to despair of any help in themselves, and to seek by faith righteousness and life in Christ the mediator. “If there had been a law given which could have given life, verily righteousness should have been by the law. But the Scripture hath concluded all under sin that the promise by faith of Jesus Christ might be given to them that believe” (Galatians 3:21-22).