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.
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.
There is nothing automatic about this, however. It is a fight, as Paul explains, between the indwelling Spirit and his desires and remaining sin (“the flesh”) and its desires. That is why there can be no sinless perfection for a believer this side of heaven. This internal fight is what keeps you from doing the things you want to do.
Paul illustrates this with his personal testimony in Romans 7:13–25. Every Christian’s soul is a theater where opposing desires — those of the Spirit versus those of the flesh — fight to be gratified. This explains why the pursuit of holiness is a struggle. We have an enemy within that rebels against the indwelling Spirit’s agenda for our lives.
Far from robbing us of assurance, the presence of spiritual conflict in a believer’s life is actually an indicator of spiritual life. Unbelievers, who do not have the Spirit living in them, may suffer from occasional pangs of conscience over their sin, but they do not experience the internal war that Paul describes to the Galatians.
After his explanation of this battle, the apostle gives us an encouragement to keep walking by the Spirit. He writes, “But if you are led by the Spirit, you are not under the law” (Gal. 5:18). He switches from the active voice (“walk”) to the passive voice (“led”), reminding us that God does not leave us to our own strength in this warfare.
As B.B. Warfied noted, “It is his [the Holy Spirit’s] part to keep us in the path to bring us at length to the goal. But it is we who tread every step of the way; our limbs that grow weary with labor.”
To walk in the Spirit is to be led by Him and to be set free from relating to the Law as a stairway to heaven. The Spirit leads us to Christ and keeps strengthening us to treasure Him so that we fight successfully against the sin that remains within.