It’s not enough to merely receive the warnings of your conscience. You’ve got to act on those warnings and deal decisively and thoroughly with the sin your conscience uncovers.
As Paul said in Romans 8:13, believers must always be “putting to death the deeds of the body.” The King James translation uses more picturesque language, exhorting us to “mortify” our sin. But what does it mean to truly kill your sin?
Mortifying your sin involves the cultivation of new habits of godliness, combined with the elimination of old sinful habits from your behavior. It is a constant warfare that takes place within the believer. Although we should expect our triumph over sin to be ever increasing, our mortification can never be wholly complete before we are glorified. We are to remain perpetually committed to the task. We must see sin as a sworn enemy, and commit ourselves to slaying it wherever and whenever it rears its head.
Scripture offers several practical means whereby believers can mortify their sin. Our growth in grace depends on our obedience to these duties. None of them are fleshly or mechanical formulas. They are not religious activities or rituals.
But sin cannot be annihilated through legalism, monasticism, pietism, asceticism, pharisaism, celibacy, self‑flagellation, confessional booths, rosary beads, Hail Marys, or any other external means. The instrument of mortification is the Holy Spirit, and His power is the energy that works in us to carry out the process. All the means of mortification are simple commands of Scripture that we are to obey. I want to highlight some of the key ones.
Abstain from fleshly lusts. Peter wrote, “Beloved, I urge you as aliens and strangers to abstain from fleshly lusts, which wage war against the soul” (1 Peter 2:11). In other words, stop lusting. Abstain from it. Stay away from it. “Flee immorality” (1 Corinthians 6:18). What could be more direct?
Do you want to put to death the lusts in your heart? Then stop entertaining them. Peter does not prescribe a program of therapy. He does not suggest that it be treated as an addiction. He simply says abstain. Quit doing it. There is no point waiting for some heavenly power to erase this sin automatically from your life. You are to stop it, and stop it immediately.
Here is perhaps the most straightforward, obvious means of mortifying our sin: stop doing it. Too many people think they must wait for an extraordinary experience, a miracle from heaven, a sign from the Lord, or whatever. They think divine intervention is necessary to free them from a sinful practice or pattern of thinking. No, that is precisely the error Romans 6 refutes. You are free from sin; now stop doing it. “Abstain.” Reckon yourself dead to sin and don’t do it anymore. “Resist the devil and he will flee from you” (James 4:7). It really is as simple as that.
Make no provision for the flesh. In Romans 13:14 Paul writes, “Put on the Lord Jesus Christ, and make no provision for the flesh in regard to its lusts.” In other words, simply refuse to accommodate fleshly lusts. If you struggle with gluttony, don’t load up on junk food when you shop at the market. If you are tempted with sexual desire, don’t fill your mind with images that feed your lust. If you don’t want to fall, don’t walk where it is slippery. Refuse to furnish your mind with the means to entertain evil thoughts. Make no preparations for the possibility of sin. Thus you can slay sin before it breeds.
Fix your heart on Christ. The apostle John wrote, “We know that, when He appears, we shall be like Him, because we shall see Him just as He is. And everyone who has this hope fixed on Him purifies himself, just as He is pure” (1 John 3:2-3).
As we fix our hearts on Christ, we discover our worship has the effect of conforming us to His image: “But we all, with unveiled face beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as from the Lord, the Spirit” (2 Corinthians 3:18).
Meditate on God’s Word. The psalmist wrote, “Thy word I have treasured in my heart, that I may not sin against Thee” (Psalm 119:11). The Lord told Joshua, “This book of the law shall not depart from your mouth, but you shall meditate on it day and night, so that you may be careful to do according to all that is written in it; for then you will make your way prosperous, and then you will have success” (Joshua 1:8). Do you want to have success in the battle against sin? Familiarize yourself with the Word of God. Meditate on it “day and night” (cf. Psalm 1:2). Let it be a lamp to your feet and a light to your path (Psalm 119:105). As the truth begins to penetrate our hearts and minds, it will confront and attack our sin.
Jesus prayed, “Sanctify them in the truth; thy word is truth” (John 17:17). The truth of God’s Word is the medium the Holy Spirit uses in our sanctification. Load your mind with it. Fill your heart with it. Ponder it carefully and let it direct your walk. “Let the word of Christ richly dwell within you” (Colossians 3:16). You will discover that “the sword of the Spirit, which is the word of God” (Ephesians 6:17), is the most effective weapon for hacking the flesh to pieces.