What the Law Could Not Do, God Did
February 4, 2026
“For God has done what the law, weakened by the flesh, could not do. By sending his own Son in the likeness of sinful flesh and for sin, he condemned sin in the flesh, 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 8:3–4)
We are slowly working our way through Romans 8, a chapter that has often been called the greatest chapter in the greatest letter ever written. Last time we considered Romans 8:1–2 and saw two great truths of the Christian life: in Christ there is no condemnation, and by the Spirit there is real freedom from the power of sin. Romans 8:3–4 now explains how God has done this. How can condemned sinners be justified and then actually begin to live holy lives?
An old poem often attributed to Puritan John Bunyan, and author of Pilgrim’s Progress, captures the heart of these verses:
“Run, John, run, the law commands,
But gives me neither feet nor hands.
Far better news the gospel brings,
It bids me fly and gives me wings.”
Romans 8:3–4 explains why that poem is true. The law commands, but it cannot empower. The gospel both commands and supplies the power.
1. What the Law Cannot Do (Romans 8:3a)
Paul writes, “For God has done what the law, weakened by the flesh, could not do.” Here “the law” means the law of God given through Moses, God’s holy and righteous commandments. The problem, Paul insists, is not with the law itself but with us. The law is “weakened by the flesh.” In other words, the law is good, but our fallen, sinful nature is not.
What, then, can the law not do? In the flow of Romans 8, at least two things are in view.
- The law cannot justify us. Romans 8:1 has just declared that there is no condemnation for those who are in Christ Jesus. That verdict of “no condemnation” does not come through law-keeping. It comes only through union with Christ by faith. The law can expose our guilt, but it cannot remove it.
- The law cannot sanctify us. Romans 8:2 speaks of “the law of the Spirit of life” setting us free from “the law of sin and death.” True moral transformation, real progress in holiness, does not come from the external pressure of commands but from the internal power of the Holy Spirit.
So the law cannot make us right with God, and it cannot change our hearts. It reveals sin, stirs up sin, and condemns sin, but it cannot save from sin. Paul has already said that the law came “in to increase the trespass” and that through the commandment “sin might become sinful beyond measure” (Romans 5:20; 7:13). A helpful image here is that of a magnifying glass. A magnifying glass does not remove any stains. It simply makes what is already there easier to see. That is what God’s law does with our sin.
This matters deeply! If justification and, as a result, sanctification do not happen in our lives, there is no eternal life. If we rely on the law, on our moral performance, on our ability to “clean up our lives,” we will only end up more clearly condemned. The law can diagnose the disease, but it cannot cure it. It can point out the problem, but can do nothing to resolve it.
2. What God Has Done (Romans 8:3b)
If the law cannot justify or sanctify, what hope is there? Paul answers:
“For God has done what the law, weakened by the flesh, could not do. By sending his own Son in the likeness of sinful flesh and for sin, he condemned sin in the flesh.”
This verse contains one of the clearest summaries of the gospel in Scripture. Notice several phrases.
a. “God has done”
Salvation is first and foremost God’s work, not ours. He does not meet us halfway. This isn’t some kind of 50/50 transaction. It isn’t even a 99/1 deal. No. He acts decisively and graciously on our behalf. The initiative is entirely His.
b. “By sending his own Son”
The Father sends the Son. This implies the Son’s eternal preexistence. Before he was “born of woman,” he already was the beloved Son with the Father, sent from heaven. The mission of God’s plan of salvation begins in the heart of the triune God, prior to creation, to send the Son to die, rise, and redeem.
c. “In the likeness of sinful flesh”
This is very careful language. Paul does not say Christ came in “sinful flesh,” as if Jesus were a sinner. Nor does he say he came merely “in the likeness of flesh,” as if he only appeared to be human, but wasn’t (i.e. the early church heresy known as “docetism”). Rather, the eternal Son truly took on human nature. He was fully man, yet without sin. He assumed our humanity, but not our guilt or corruption through Adam. He entered our world and our human weakness (Hebrews 2:17), yet remained perfectly holy and without sin (2 Corinthians 5:21).
d. “And for sin”
The phrase “for sin” is sacrificial language. It echoes the Old Testament “sin offering.” Jesus comes not only as a teacher or example, but as the true and only sacrifice for sin. He is the fulfillment of every lamb that was ever slain under the old covenant (Hebrews 9:13-14, 22).
e. “He condemned sin in the flesh”
Here now is the heart of the matter! God did not leave our sin unpunished. He condemned it. But he condemned it “in the flesh” of his Son. The condemnation we deserved fell on Christ (Romans 3:25-26). The righteous One stood in the place of the unrighteous. As Paul says, “For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God” (2 Corinthians 5:21).
This is how there can now be “no condemnation” for those who are in Christ Jesus. Our condemnation has already occurred, at the cross, in him!
3. Why God Did It (Romans 8:4)
Paul does not stop with justification. Verse 4 explains God’s purpose:
“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.”
God’s goal is not only to declare us righteous but also to make us righteous in practice. The “righteous requirement of the law” is fulfilled in us, not merely for us. And what is the righteous requirement of the law? Jesus summarized the law in two commands: love God with all your heart, soul, and mind, and love your neighbor as yourself (Matthew 22:27-30). Paul later writes, “Love is the fulfilling of the law” (Romans 13:10).
God’s purpose, then, is to create a redeemed people who genuinely love Him and love others. The law itself could not produce this, because it remains external to the heart. But the Spirit can. In the new covenant, God not only forgives sins, he gives a new heart and writes his law within (Ezekiel 36:26-27; Jeremiah 31:33-34). The result is that believers “walk not according to the flesh but according to the Spirit.”
This means that the same grace that justifies us also now sanctifies. The death of Christ not only secures our pardon but also secures the gift of the Spirit, who begins in us a lifelong work of transformation. We are set free from the penalty of sin and we are set free from its enslaving power.
Living in What God Has Done
For the believer, Romans 8:3–4 calls us away from self-reliance and toward Christ reliance. We do not look to the law to save or to change us. We look to Christ crucified and risen, and we depend on the Spirit he has given. As we fix our minds and hearts on him, the Spirit produces in us what the law could never create: genuine love, real obedience, and growing likeness to Christ.
For those who are not yet in Christ, the unbeliever, these verses issue a gracious invitation. Christianity is not a project of self-improvement or a program of moral reform. It is good news about what God has done in his Son. The law cannot save. Christ can, and he has done everything necessary. The call of the gospel is to turn from trusting yourself and to rest in him.
What the law could not do, God has done. That is the hope, the comfort, and the calling of Romans 8:3–4.
