The sin that remains in a Christian never stops desiring to regain the place of dominion it previously enjoyed before its power was broken at regeneration. Sinful desires remain in even the most mature believer, but as the believer treasures Christ above everything else, temptations are resisted and the desires of the flesh will not be gratified.
The Christian life is a war, and the fiercest battles are those that rage within the heart of every believer. The new birth radically and permanently changes a person’s sinful nature, but it does not immediately liberate that nature from all of the remnants of sin. Birth is followed by growth, and that growth involves warfare.
Paul frequently employs the imagery of warfare to help Christians faithfully follow Christ. In Galatians 5 he gives us a peek behind the scenes to help us understand why the soul of one who has been redeemed by Jesus Christ is such a battleground.
“But I say, walk by the Spirit, and you will not gratify the desires of the flesh. For the desires of the flesh are against the Spirit, and the desires of the Spirit are against the flesh, for these are opposed to each other, to keep you from doing the things you want to do. But if you are led by the Spirit, you are not under the law” (vv. 16–18).
From the point of the new birth, every Christian is indwelt by God Himself through the ministry of the Holy Spirit. Jesus promised this indwelling presence (John 14:17) and Paul refers to it earlier in the Galatian letter (3:2, 5), and elsewhere he teaches that the person who is not indwelt by the Spirit does not have Christ (Rom. 8:9).
The only way that believers can be victorious in the battle within is through the power of the Holy Spirit. Paul makes this point by giving the Galatians (and us) a command, a promise, an explanation, and an encouragement.
Christians are commanded to “walk by the Spirit.” This is a call to all believers to live in the power of the Holy Spirit, to be consciously under His control. More specifically, Paul is instructing us to follow the Holy Spirit’s agenda. How do we know what that is? Jesus tells us in John 16:13–14: “When the Spirit of truth comes, he will guide you into all the truth, for he will not speak on his own authority, but whatever he hears he will speak, and he will declare to you the things that are to come. He will glorify me, for he will take what is mine and declare it to you.”
Believers glorify Christ when we treasure Him above everything else in life. The Spirit empowers us to do this by trusting in the Lord, rejoicing in Him, and keeping His commandments through all of the ups and downs of life. Walking by the Spirit means adopting His purpose and relying on His strength to make Jesus Christ known.
The promise attached to this command is that as we live this way, we “will not gratify the desires of the flesh.” By “flesh” Paul does not mean our physical bodies; rather, he refers to our fallen nature, to our old ways of life that are in opposition to God.
