Be Killing Sin

For if ye live after the flesh, ye shall die: but if ye through the Spirit do mortify the deeds of the body, ye shall live. ROMANS 8:13

The Mortification of Sin in Believers is an exposition of one verse. Owen takes Paul’s words in Romans 8:13 and finds in them a whole map of the Christian’s inner war: a duty (mortify the deeds of the body), the people to whom it is given (ye, believers), the power by which it is done (through the Spirit), and a promise attached to it (ye shall live). To mortify, he explains, is simply to put to death. Sin in the believer is pictured as a living thing, an old man with his own strength and cunning, and the command is to take away its life.

The word sounds old-fashioned now, and to many ears it suggests hair shirts and cold baths. Owen means nothing of the kind, as later chapters will show. He means the daily, deliberate, Spirit-given work of weakening the sin that still lives in a Christian, so that it loses its power to rule.

Even the best believers

The first thing Owen establishes is the most surprising: this work is for Christians, and for the best of them. He puts it as a thesis at the head of his argument: “The choicest believers, who are assuredly freed from the condemning power of sin, ought yet to make it their business all their days to mortify the indwelling power of sin.”

He proves it from Paul’s letter to the Colossians. The people told to mortify their members which are upon the earth are the very people who are risen with Christ, dead with Him, and hidden with Him in God.

Mortify therefore your members which are upon the earth; fornication, uncleanness, inordinate affection, evil concupiscence, and covetousness, which is idolatry. COLOSSIANS 3:5

Then comes the sentence for which Owen is remembered. Being dead with Christ, he says, will not excuse you from this work: “Do you mortify; do you make it your daily work; be always at it whilst you live; cease not a day from this work; be killing sin or it will be killing you.”

Owen first spoke it to young Christians at Oxford. He was not frightening unbelievers; he was telling believers that forgiveness does not end the fight. It begins it.

Why the fight never stops

Owen gives his reasons with characteristic thoroughness, and they are worth hearing slowly.

First, sin remains. There is no perfection in this life. Paul himself said he had not yet attained, and the flesh still lusts against the Spirit in every Christian.

For the flesh lusteth against the Spirit, and the Spirit against the flesh: and these are contrary the one to the other: so that ye cannot do the things that ye would. GALATIANS 5:17

Second, sin is active. It does not merely sit in the heart; it works. Owen has a memorable image for its stillness: “sin is never less quiet than when it seems to be most quiet.” Its waters are deepest where they are calmest. And so, he concludes, “There is not a day but sin foils or is foiled, prevails or is prevailed on.” There are no neutral days.

Third, sin aims at the worst. Every temptation, if it had its way, would go to the limit of its kind. “Every unclean thought or glance would be adultery if it could; every covetous desire would be oppression, every thought of unbelief would be atheism, might it grow to its head.” Sin starts modestly, asking only a little ground, but it never means to stop there.

But every man is tempted, when he is drawn away of his own lust, and enticed. Then when lust hath conceived, it bringeth forth sin: and sin, when it is finished, bringeth forth death. JAMES 1:14–15

Fourth, God has given the Spirit and the new nature precisely so that we may fight. To leave that gift idle, Owen says, is like binding the arms of the one who fights for you while leaving your enemy free to strike.

Fifth, neglect leads to decline. Grace withers when it is not exercised, and the heart grows hard. Owen had watched it happen. He describes Christians he had known as humble, tender and zealous who, through neglecting this duty, had become earthly, cold and quick-tempered.

But exhort one another daily, while it is called To day; lest any of you be hardened through the deceitfulness of sin. HEBREWS 3:13

Life, vigour and comfort

What is promised to those who do this work? Ye shall live. Owen is careful here. Mortification is not the cause of eternal life, which is the free gift of God; it is the appointed way to it, the means God has joined to the end. But he also hears in the promise something for this life: a vigour and comfort in walking with God. “The vigour, and power, and comfort of our spiritual life depends on the mortification of the deeds of the flesh.”

He uses a gardener’s picture. Two plants of the same kind are set in two plots. One plot is left to the weeds, and the plant lives but can hardly be found. The other is weeded daily, and the plant flourishes. The graces of the Spirit, Owen says, are like that. They may be truly present in a neglected heart and yet so choked that faith, love and zeal can scarcely be seen.

Every branch in me that beareth not fruit he taketh away: and every branch that beareth fruit, he purgeth it, that it may bring forth more fruit. JOHN 15:2

He is honest that the connection is not mechanical. He points to Heman, the writer of the eighty-eighth Psalm, who walked with God faithfully and yet had terrors for his portion all his days. God keeps it in His own hand to speak peace and comfort. But in the ordinary course of things, an unmortified sin will weaken the soul and darken it, and nothing but mortification will clear the sky.

A word of caution

Owen can be misread in two directions. Some readers, sensitive and scrupulous, hear his warnings and turn them on themselves until every flicker of temptation seems proof that they are lost. Owen did not intend this, and later in the book he says plainly that finding sin in yourself proves nothing either way about whether you are a Christian. The work of mortification is done by people who are already forgiven, in the light of that forgiveness. If you are reading him in a way that leaves you further from Christ, you are reading him wrongly.

Others hear the call and make it a programme of self-improvement, as if holiness were a matter of discipline and technique. Owen will close that door firmly in the next chapter. The fight is real, and it is ours; but it is fought through the Spirit, or not at all.

Though our outward man perish, yet the inward man is renewed day by day. 2 CORINTHIANS 4:16

Between those two errors lies the plain path of Romans 8:13. There is sin in you. It is alive and it means your harm. God has given you His Spirit to put it to death. Do not make peace with it for a single day.

FOR REFLECTION AND ACTION

1. Go back to the sin you wrote down at the start of this book. Ask whether you have been fighting it daily, occasionally, or not at all.

2. Owen says there are no neutral days: sin either foils or is foiled. At the end of each day this week, ask which it was, and bring the answer to God.

3. Think of a small temptation you have been treating as harmless. Follow it in your mind to where it would go if it had its way, and let that sober you.

4. Read Colossians 3:1–10 and notice how Paul grounds the command to mortify in what is already true of you in Christ.

A PRAYER

Holy Father, I confess that I have made peace with sins that You have told me to put to death.

Thank You that there is now no condemnation for those who are in Christ Jesus, and that I fight not to be forgiven but because I am.

Give me the daily watchfulness Your servant Owen urged, so that I do not rest while my enemy is still alive.

Through Your Spirit, weaken what is evil in me and strengthen every grace You have planted, until I bear more fruit for Your glory. Amen.