After establishing that the inheritance comes through the Abrahamic promise and not through the Mosaic law, Paul anticipates the most obvious objection with a direct question in Galatians 3:19: "Why then the law?" It is a fair question. If the law cannot justify, cannot give life, and cannot annul the prior promise - what was it doing for 1,500 years of Israel's history?

Paul's answer is precise and carefully bounded. The law had a real purpose. It was not a mistake. But its purpose was specific, temporary, and never designed to accomplish what the Hebrew Roots Movement asks it to accomplish today.

Purpose One: To Define and Expose Sin

The first and most fundamental purpose of the law was to make sin visible and concrete. Paul states this plainly in Romans 3:20: "Through the law comes knowledge of sin." And again in Romans 7:7: "I would not have known what it is to covet if the law had not said, 'You shall not covet.'"

The law does not cure sin. It diagnoses it. A thermometer that reveals a fever is doing its job - but no one mistakes the thermometer for the medicine. The law was given to show humanity the precise nature and extent of its problem, not to solve it.

Purpose Two: To Confine and Imprison

Galatians 3:22–23 describes the law's role in stark terms: "The Scripture imprisoned everything under sin, so that the promise by faith in Jesus Christ might be given to those who believe. Now before faith came, we were held captive under the law, imprisoned until the coming faith would be revealed."

This is a deliberate confinement. The law held Israel in a holding pattern - not as a punishment, but as a controlled environment that preserved the people through whom the Seed would come, until the appointed moment of fulfilment.

Purpose Three: To Point Forward

Every element of the Mosaic system was anticipatory. Hebrews 10:1 describes the law as containing "a shadow of the good things to come instead of the true form of these realities." The sacrificial system, the priesthood, the festivals, the Day of Atonement - none of these were ends in themselves. They were rehearsals. Models. Previews of a reality they could point toward but never themselves provide.

When the reality arrives, the shadow has served its purpose. Insisting on continuing the shadow after the substance has come is not deeper faithfulness - it is a refusal to look up from the picture and see the person the picture was always about.

Purpose Four: To Guard and Discipline

Galatians 3:24–25 gives the law its final role: "The law was our guardian until Christ came, in order that we might be justified by faith. But now that faith has come, we are no longer under a guardian." The guardian's role ends when the heir comes of age. That moment has come. The guardian has been honourably discharged. To demand his continued authority is to misunderstand his role from the beginning.

What the Law Cannot Do - Let Scripture Speak

Having understood what the law was designed to do, we must be equally clear about what it was never designed to do. This is not a minor theological footnote. It is the precise point at which the Hebrew Roots Movement goes wrong - and Scripture addresses each failure directly.

The law cannot justify.
"By works of the law no human being will be justified in his sight." (Romans 3:20)
"A person is not justified by works of the law but through faith in Jesus Christ." (Galatians 2:16)
"Now it is evident that no one is justified before God by the law." (Galatians 3:11)

The law cannot give life.
"If a law had been given that could give life, then righteousness would indeed be by the law." (Galatians 3:21)
The conditional form of Paul's statement is telling. Such a law was never given - because the law was never designed to be a life-giving instrument.

The law cannot make righteous.
"For if righteousness were through the law, then Christ died for no purpose." (Galatians 2:21)
If law-keeping could produce righteousness before God, the cross was unnecessary. The logic is inescapable: either the cross was necessary, or righteousness was available through Torah. It cannot be both.

The law cannot sanctify.
"Are you so foolish? Having begun by the Spirit, are you now being perfected by the flesh?" (Galatians 3:3)
Paul's question to the Galatians is direct: the Christian life began in the Spirit - do you imagine it is completed through external observance? Sanctification through law-keeping is not a deeper form of spirituality. Paul calls it foolishness.

The law cannot free from sin's power.
"For sin will have no dominion over you, since you are not under law but under grace." (Romans 6:14)
Remarkably, Paul says that being under law is associated with sin's ongoing dominion, not freedom from it. The law defines sin but cannot break its power. It diagnoses the disease but cannot administer the cure.

The law cannot produce the obedience it demands.
"For God has done what the law, weakened by the flesh, could not do." (Romans 8:3)
The law's failure is not a flaw in the law. It is a flaw in us. The law is holy and good - but it operates on material (fallen human nature) that cannot fulfil it. It commands what the flesh cannot deliver.

The law cannot cleanse the conscience.
"Gifts and sacrifices are offered that cannot perfect the conscience of the worshipper." (Hebrews 9:9)
"It is impossible for the blood of bulls and goats to take away sins." (Hebrews 10:4)
The entire sacrificial machinery of the Mosaic system - offered year after year, day after day - could never reach the conscience. It could not accomplish what only a final, perfect, once-for-all sacrifice could do.

What the Holy Spirit Actually Does

Here is where the argument reaches its most important destination. Everything the law was unable to accomplish, God has provided through his Spirit. This is not a theoretical substitute - it is the specific provision of the New Covenant, foretold by the prophets and delivered through Christ.

The Spirit justifies.
"You were justified in the name of the Lord Jesus Christ and by the Spirit of our God." (1 Corinthians 6:11)

The Spirit gives life.
"The letter kills, but the Spirit gives life." (2 Corinthians 3:6)
"The law of the Spirit of life has set you free in Christ Jesus from the law of sin and death." (Romans 8:2)

The Spirit produces righteousness.
"For we through the Spirit, by faith, wait for the hope of righteousness." (Galatians 5:5)
"In order that the righteous requirement of the law might be fulfilled in us, who walk not according to the flesh but according to the Spirit." (Romans 8:4)
This last verse is stunning in its precision: the Spirit accomplishes in believers the very righteous standard the law required but could not produce. The goal of the law is reached - but through the Spirit, not through law-keeping.

The Spirit sanctifies.
"You were sanctified… by the Spirit of our God." (1 Corinthians 6:11)
"God chose you as the firstfruits to be saved, through sanctification by the Spirit." (2 Thessalonians 2:13)

The Spirit writes the law on the heart.
"I will put my law within them, and I will write it on their hearts." (Jeremiah 31:33)
"I will put my Spirit within you, and cause you to walk in my statutes." (Ezekiel 36:27)
The New Covenant does not abolish moral obligation - it internalises it. The Spirit does not remove the standard; he creates the desire and the capacity to meet it from the inside. External observance of a written code is replaced by inward transformation through the living God.

The Spirit frees from sin's dominion.
"For the law of the Spirit of life has set you free in Christ Jesus from the law of sin and death." (Romans 8:2)
"Where the Spirit of the Lord is, there is freedom." (2 Corinthians 3:17)

The Spirit produces what the law demanded but could not generate.
"The fruit of the Spirit is love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control; against such things there is no law." (Galatians 5:22–23)
Every moral quality the law demanded - love, faithfulness, self-control - the Spirit produces as fruit in the life of the believer. And Paul's closing observation is quietly devastating: "against such things there is no law." The person walking in the Spirit has already exceeded what the law was trying to produce.

The Conclusion Paul Reaches

The contrast could not be more complete. The law exposes sin; the Spirit forgives and cleanses it. The law commands righteousness; the Spirit produces it. The law is written on stone; the Spirit writes on the heart. The law could not free from sin's dominion; the Spirit breaks it. The law demanded obedience the flesh could not render; the Spirit creates the desire and the capacity to obey from within.

This is not a diminishment of the law. Paul insists the law is holy, righteous, and good (Romans 7:12). Its diagnosis was accurate. Its standards were God's own. But a perfect diagnosis is not a cure - and the law was never the cure. The cure is the Spirit of the living God, given freely to all who are in Christ.

Returning to the law as the framework of the spiritual life is therefore not going deeper. It is reaching back past the cure to the diagnosis - insisting on the thermometer when the fever has already been broken.

For the law of the Spirit of life has set you free in Christ Jesus from the law of sin and death. For God has done what the law, weakened by the flesh, could not do. - Romans 8:2–3