Sin. It is everywhere. It is never dormant. It is not passive. It does not sleep. It actively weakens and darkens the soul of every human being and has done so since the Fall (Genesis 3). Sin tempts our will. It separates us from our Father. It deceives our hearts and hardens men to the gospel. And apart from Christ, we are utterly hopeless against it.

The Christian, redeemed and sustained by the finished work of Christ, must wage war against sin.

“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 8:13)

“PUT TO DEATH THE DEEDS OF THE BODY…”

Seldom is written these days about how to “put to death the deeds of the body.” Thankfully, the Puritan writers were not silent on the issue. John Owen called it the mortification of sin. In his treatise The Mortification of Sin in Believers, he writes:

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… Do you mortify; do you make it your daily work; be always at it while you live; cease not a day from this work; be killing sin or it will be killing you.

If sin is out to kill me, then I ought to know how to kill it first—mortify it.

SEVEN WAYS TO MORTIFY SIN.

Consider these seven ways we can wage war against sin.

  1. YOU MUST BE A CHRISTIAN—BELIEVE UPON THE GOSPEL.

There is no victory apart from Christ. His good news is “the power of God unto salvation to everyone who believes” (Romans 1:16). Without Him, any war that you wage against your indwelling sins will consequently fail.

“When the perishable puts on the imperishable, and the mortal puts on immortality, then shall come to pass the saying that is written: ’Death is swallowed up in victory.’ ’O death, where is your victory? O death, where is your sting?’ The sting of death is sin, and the power of sin is the law. But thanks be to God, who gives us the victory through our Lord Jesus Christ” (1 Corinthians 15:54-57).

  1. KNOW YOUR ENEMY.

First, you must know your enemy within indwelling sin. “For out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false witness, slander” (Matthew 15:19). Know your sins and call them what they are. Looking at porn and flirting with your neighbor’s wife is not innocent play; it is spiritual adultery (Matthew 5:28). Cursing at the traffic jam on the I-5 is not a mild slip of the tongue; it is a sin of the tongue (James 3:8). If you turn a blind eye to the weight of your sins, you will end up neglecting your need for God’s grace.

Second, know the enemy hunting after you. The Bible tells us to “be sober-minded; be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour” (1 Peter 5:8). Our enemy prowls around day and night looking to consume us. He (Satan) is not passive—he is active—so we should not be either.

  1. PUT ON YOUR ARMOR (PRAY).

You would not step into a flurry of gunfire without your bulletproof vest and helmet on, especially if they have been provided to you. When you got saved, you entered a spiritual battle (Ephesians 6:12) and, likewise, your armor and weaponry has been provided:

“Therefore take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand firm. Stand therefore, having fastened on the belt of truth, and having put on the breastplate of righteousness, and, as shoes for your feet, having put on the readiness given by the gospel of peace. In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one; and take the helmet of salvation, and the sword of the Spirit, which is the word of God, praying at all times in the Spirit, with all prayer and supplication. To that end keep alert with all perseverance, making supplication for all the saints, and also for me, that words may be given to me in opening my mouth boldly to proclaim the mystery of the gospel, for which I am an ambassador in chains, that I may declare it boldly, as I ought to speak.” (Ephesians 6:13-20)

  1. STORE GOD’S WORD IN YOUR HEART AND USE IT.

We agree with the reformer Martin Luther, who affirmed, “When the Scripture speaks, God speaks.” Biblical truths and revelation are used by God the Holy Spirit to make us more and more like Jesus. Therefore, we need to listen to what the Bible says, learn what it teaches, store it in our hearts, and make every effort by the Holy Spirit’s empowering grace to mortify our sin and be transformed by the renewing of our minds.

“I have stored up your word in my heart, that I might not sin against you.” (Psalm 119:11)

“For the word of God is living and active, sharper than any two-edged sword, piercing to the division of soul and of spirit, of joints and of marrow, and discerning the thoughts and intentions of the heart.” (Hebrews 4:12)

  1. TAKE RESPONSIBILITY.

Sometimes, we think to ourselves, “I just need to get supernaturally zapped soon by a good sermon or devotional. Once God does this, then I’ll kick my sin to the curb!” Before long, we remain unzapped, and God is to blame: “After all, He knew very well what I needed, and He didn’t follow through.” This is cowardly thinking.

One of the biggest misconceptions of the sovereignty of God is that it excuses us from any responsibility. False. God is working in us both to will and to work for His good pleasure (Philippians 2:13). He gives us the power, but we are responsible; we are called to both godliness and obedience. No excuses. And here’s the best part: even though we are responsible, it is God who does the work in us! Thus, because the Holy Spirit is in you, kill your sin!

“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 8:13)

  1. LAY HOLD OF YOUR VICTORY IN CHRIST.

To wage war against sin is not to destroy it. That is Jesus’ job, not ours. Nonetheless, Jesus is risen today in triumphant victory over Satan, sin, and death. Through Christ and His gospel, God Almighty has provided us His power for salvation (Romans 1:16). Lay hold of it and rejoice in his victory!

“But God, being rich in mercy, because of the great love with which he loved us, even when we were dead in our trespasses, made us alive together with Christ—by grace you have been saved…” (Ephesians 2:4-5)

  1. JOIN A LOCAL CHURCH AND COMMIT TO HER.

A lot could be said about the biblical need for membership in a local church, but we will save that for another day. For now, I’ll let Pastor Mark Dever speak. In The Deliberate Church, he writes, “The nature of the Christian life is corporate because the body of Christ is a corporate entity. While our individual walks are crucial, we are impoverished in our personal pursuit of God if we do not avail ourselves of the help that is available through mutually edifying relationships in our covenant church family (Ephesians 4:15-16; Hebrews 10:24-25).”

We are members of a church body, not just when we desire to be, but always. If we desire to be a healthy body, we need to meet and fellowship with one another as God commands us to. For the sake of gospel-advancement in our cities and gospel-evidence in our lives, we must join a local a family of believers. Make it a home and a family. There you will find prayer, fellowship, discipleship, and accountability.

CONCLUSION

At the end of the day, God alone is our hope from sin. After all, He is an active participant in each of the previous steps. It is God’s gospel who saves, God’s armor we wear, God’s Word we hide, God’s victory we claim, God’s church we are members of. In all of our war-waging, we rest in God’s promise to keep His own:

“Now to him who is able to keep you from stumbling and to present you blameless before the presence of his glory with great joy, to the only God, our Savior, through Jesus Christ our Lord, be glory, majesty, dominion, and authority, before all time and now and forever. Amen.” (Jude 24-25)