Romans 8: Mortifying Sin

“So then, brothers, we are debtors, not to the flesh, to live according to the flesh. For if you live according to the flesh you will die, but if by the Spirit you put to death the deeds of the body, you will live.” – Romans 8:12-13

We come now to one of those verses where a mere 1500 words cannot do justice to the full force of what Paul is saying. Indeed, the great John Owen himself wrote three books unpacking this very verse, totaling more than 500 pages![1] And yet sadly this is a verse and theological theme many have either neglected in today’s church, or if they do focus on it, get it dreadfully wrong. The Church of Christ is always swinging either to the extreme of antinomianism (that is, a licentiousness and general pattern of immorality) or to the extreme of legalism (that is, pursuing holiness through human effort alone and through extra-biblical laws and traditions). Neither are biblically right, and both are spiritually deadly. The opposite of each extreme is the Gospel of Jesus Christ. Which is why Paul has spent 11 verses thus far making sure we’ve been grounded in what it means to be a true believer.

His major thesis is this: If we continue to live our lives under the power of the flesh – that is, a fallen sinful nature – then it is a life that is showing itself to be spiritually dead and it will be a life that ends in physical and eternal death. That’s the first part of verse 13. “For if you live according to the flesh you will die.”

And look, this is important to consider. There are many people who have fooled themselves into thinking they’re right with God simply because they’ve prayed a prayer (which, by the way, is not in the Bible as something we do to be right with God – Jesus never commanded us to pray a “sinner’s prayer” in order to go to heaven). And these folks who have fooled themselves are in grave danger of eternal death because they think on the one hand that they’re going to heaven because they’ve prayed this prayer, but on the other hand their lives show no evidence of being born-again and having the Holy Spirit – they are still living according to the flesh. They give in to temptation without any fight, they let their anger control them (they might even be mad right now at reading these words!), they’re controlled by a consistent pattern of lust, or lying, or laziness. Or maybe their sin is that they consistently trust in themselves! They work hard, they’re good citizens, and they take care of their family, they even go to church! But damnably they think that all of that will get them right with God. They do not know that their “righteous deeds are as filthy rags” (Isaiah 64:6). In other words, their whole life is one which fits in with the world. They may be Republican or Democrat, black, white, Asian, or Latino, but the one thing they are not is changed by the Holy Spirit.

“If you live according to the flesh you will die,” says Paul. But he doesn’t stop there. There is an opposite way of living which leads not to death but to eternal life. “But if by the Spirit you put to death the deeds of the body, you will live.” First, we need to see that this second way of living only comes about by the power of the Holy Spirit. That’s really been the thrust of Paul’s argument so far in Romans 8. If we’re in Christ then Christ is in us, by His Spirit, and therefore we have all the benefits of and power of the Holy Spirit. And so whatever else Paul says in this verse, none of it makes sense outside of the presence of the saving power of God’s Spirit which comes through our faith in Christ.

The second thing we need to see is that Paul is speaking to Christians here, yes, but he’s also emphasizing the responsibility Christians have in this work of “putting to death the deeds of the flesh.” So whatever that means, to put to death the deeds of the flesh, notice first that it is something Christians must actively pursue! They have a responsibility to be doing that work. This doesn’t mean, of course, that this is something we do all by ourselves. No! Paul says here, “If you, by the Spirit, put to death…”; do you see? God is sovereignly working in us to put to death sin and temptation, but the emphasis Paul has here is on you, your responsibility. Listen to how Octavius Winslow understands this:

“If ye – the believer is not a cipher in this work. It is a matter in which he must necessarily possess a deep and personal interest. How many and precious are the considerations that bind him to the duty! His usefulness, his happiness, his sunny hope of heaven, are included in it. The work of the Spirit is not, and never was designed to be, a substitute for the personal work of the believer. His influence, indispensable and sovereign though it is, does not release from human and individual responsibility.”[2]

This is consistent with what Paul expresses elsewhere. Consider Philippians 2:12-13. Paul commands Christians to, “work out your own salvation with fear and trembling.” This is their responsibility; it is a duty they must actively pursue. And yet in the very same sentence he can also say, “for it is God who works in you, both to will and to work for his good pleasure.” That is, your work is also God’s work in you! So, what is this work to which Christians must give themselves, lest they die and forfeit eternal life? Read the rest of verse 13: “if by the Spirit you put to death the deeds of the body, you will live.”

Older translations used the great word mortify for the phrase “put to death” and it means just that: to kill, to destroy, to execute and entirely put to death. What is to be killed, according to Paul? Simply, the deeds of the flesh. Paul doesn’t mean here our physical flesh. We’re not to be masochists (those who take pleasure in self-inflicted pain) and neither does he mean here a monkish kind of asceticism (living meagerly under crude conditions).[3] What he means is that we are to put to death our evil and sinful inclinations, our deformed desires that are not in line with and submitted to God’s law. This will include then every part of our lives, including our physical bodies – what we do with our eyes, our ears, our hands, our tongues, our minds, and our hearts; especially our hearts! Our hearts control everything about us which expresses a desire to sin and so we’re called here to kill those desires. As Paul says of himself in 1 Corinthians 9:27, “I discipline my body and keep it under control, lest after preaching to others I myself should be disqualified.”

The biblical picture of mortification is actually that of crucifixion. The same language used here of putting the deeds of our flesh to death is also used of the Roman guards who put Jesus to Death. Which means we have a model of how we’re supposed to fight against and kill sin in what happened to Christ. Again, Octavius Winslow remarks that “Death by the cross is certain, yet lingering. Our blessed Lord was suspended upon the tree from nine in the morning until three in the afternoon. It was a slow, lingering torture, yet terminating in his giving up the ghost. Similar to this is the death of sin in the believer. It is progressive and protracted, yet certain in the issue. Nail after nail must pierce our corruptions, until the entire body of sin, each member thus transfixed, is crucified and slain.”[4]


I think we can say more than that! Just as the Pharisee’s and the Romans guards condemned Jesus, mocking him and taunting him, so must we do with our sin. They did so unjustly, we do so justly and commanded by God! Drag your sin our into the public, into the light of day, just as the guards did to Christ, and then crucify your sin – hang it up for all to see and let it suffocate in its public shame and nakedness, no longer covered under darkness and privacy, but pierced through and whipped so that it is no longer recognizable under your mortification. Just as the guards were ruthless with Christ, so much more ought we to be with our sin which sent Christ to the cross! The Pharisee’s hated Jesus. Do you hate your sin more than they hated our Savior? Or do you coddle your sin and secretly love it? It takes a deep hatred to kill a man, and that is the hatred we must have for our sin. “Put to death the deeds of the body and you will live.”

When I originally wrote this meditation, we were in the beginning season of the COVID-19 pandemic, and I was writing to a church fearful of that virus. I was writing as a pastor and was sincere in telling them that I did not want them to die. But then I concluded with something a bit shocking but just as sincere. I’d much rather they die by Covid-19 yet die still faithful to the Lord, then come through the pandemic physically alive yet spiritually dead. Though the world had “shut down” in the early spring of 2020, sin and temptation took no time off and was working infinitely more than any virus to consume and kill its host. I think that’s the thrust of Paul’s emphasis here in chapter 8 verse 13. As John Owen so memorably stated and summarized the issue, “be killing sin or else sin will be killing you.”

Stephen Unthank (MDiv, Capital Bible Seminary) serves at Greenbelt Baptist Church in Greenbelt, MD, just outside of Washington, DC.  He lives in Maryland with his wife, Maricel and their two children, Ambrose and Lilou.

[1] See the volume Overcoming Sin and Temptation: Three Classic Works by John Owen, edited by Kelly M. Kapic and Justin Taylor (Crossway, 2006).

[2] Octavius Winslow, No Condemnation In Christ Jesus (The Banner of Truth Trust, 1991), p. 151-152

[3] John Stott, The Message of Romans (InterVarsity Press, 1994), p. 228

[4] Octavius Winslow, No Condemnation In Christ Jesus (The Banner of Truth Trust, 1991), p. 151


Stephen Unthank