Mortification of Sin

**"Mortify therefore your members which are upon the earth; fornication, uncleanness, inordinate affection, evil concupiscence, and covetousness, which is idolatry."** — Colossians 3:5 (KJV)

"Mortify" is a violent word. It means to put to death. To kill. To execute. Paul does not say, "Manage your sin." He does not say, "Reduce your sin." He does not say, "Hide your sin." He says: *Kill it.*

This is the doctrine of mortification — the lifelong work of putting sin to death in the power of the Holy Spirit. It is not optional. It is not advanced Christianity for the super-spiritual. It is the normal, expected life of every believer who has been united to Christ in His death and resurrection.

We do not mortify sin in order to be saved. We mortify sin *because* we are saved. The order is crucial. In Romans 6, Paul asks: "Shall we continue in sin, that grace may abound? God forbid. How shall we, that are dead to sin, live any longer therein?" (Romans 6:1-2).

The believer has already died to sin — positionally, legally, covenantally. He died with Christ on the cross. His old man was crucified. His body of sin was destroyed. This is not a future possibility; it is a present reality.

But the believer still sins. The old man is dead, but his corpse still twitches. Sin remains in the believer as a resident enemy — not reigning, but remaining. Not dominant, but disturbing. The work of mortification is the progressive experience of what is already true positionally: the death of sin and the life of righteousness.

John Owen, the greatest Puritan theologian on this subject, wrote an entire treatise on mortification. His advice is both practical and profound:

**1. Identify the sin.** Be specific. Do not say, "I struggle with lust." Say, "I look at images on my phone when I am bored at night." Do not say, "I am proud." Say, "I feel resentment when others are praised and I am overlooked." Sin hides in vagueness. It dies in specificity.

**2. Consider the guilt of the sin.** Not merely its consequences — though those are real — but its offense against God. This sin crucified Christ. This sin made the Son cry out in agony. This sin is not a minor inconvenience; it is cosmic treason against the King.

**3. Consider the danger of the sin.** Sin hardens. Sin blinds. Sin deceives. The sin you indulge today will be stronger tomorrow. The lust you feed today will demand more tomorrow. The pride you excuse today will destroy you tomorrow. Sin is a fire that consumes everything it touches.

**4. Load your conscience with the guilt of the sin.** Do not make peace with it. Do not excuse it. Do not minimize it. Let your conscience feel the full weight of your offense. This is not masochism; it is honesty. You cannot kill what you will not acknowledge.

**5. Apply the gospel to the sin.** Here is where mortification differs from mere moralism. Moralism says, "Stop sinning because it is bad." The gospel says, "Stop sinning because you are already accepted in the Beloved." Moralism kills by threatening. The gospel kills by satisfying.

When you believe that Christ has already paid for your sin, you are freed from the need to hide it. When you believe that Christ's righteousness is already yours, you are freed from the need to prove yourself. And when you are freed from hiding and proving, you are finally able to kill the sin that thrives on secrecy and self-justification.

Mortification is not a human work. It is a divine work done in and through human beings. "If ye through the Spirit do mortify the deeds of the body, ye shall live" (Romans 8:13). The Spirit is the agent. We are the instruments.

This means we cannot mortify sin in our own strength. We can resist sin for a time — by willpower, by discipline, by external constraints. But only the Spirit can kill sin at the root. Only the Spirit can change the heart's desires. Only the Spirit can make obedience a delight rather than a duty.

Our job is to use the means the Spirit has appointed: prayer, Scripture, the sacraments, fellowship, accountability. And then to trust that the Spirit is working — slowly, often invisibly, but certainly — to conform us to the image of Christ.

What sin are you nursing today? What habit have you explained away? What lust have you renamed as "preference"? What pride have you disguised as "high standards"? Name it. Acknowledge it. Confess it. And then — in the power of the Spirit, not your own strength — put it to death.

Mortification is not a one-time event. It is a lifelong war. There will be battles you lose. There will be sins that rise again after you thought them dead. But the war is already won — Christ has defeated sin at the cross — and your job is to apply that victory to the specific strongholds in your life.

Kill sin, or sin will kill you. That is the choice. And the gospel gives you the power to choose life.

Lord, I confess that I have been tolerant of sin in my life. I have excused it, hidden it, renamed it. I have tried to manage it rather than kill it. Forgive me. Show me the specific sins that still hold power over me. Give me the courage to name them, the honesty to confess them, and the Spirit's power to put them to death. Let me not be content with partial victory. Let me press on toward the fullness of holiness, knowing that Christ has already won the war and is winning the daily battles in me. In His conquering name, Amen.

*From the Reformed tradition. Scripture quotations from the King James Version.*