Galatians 5:16-17, Romans 13:14, Galatians 5:24
The Enemy Within
Of the three enemies — the world, the flesh, and the devil — the flesh is the most intimate and in some ways the most persistent. External enemies can be distanced from; the flesh is carried everywhere.
"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." (Galatians 5:17). The warfare is internal — a conflict within the believer between the new nature created by the Spirit and the residual pull of the old self.
What "The Flesh" Means
The Greek word sarx (flesh) is used in several senses in the New Testament. In the context of spiritual warfare and the Christian life, it refers not to the physical body per se but to the fallen human nature — the residual orientation toward self, sin, and independence from God that persists even in the regenerate believer.
The flesh is not the body. The body is good — created by God, redeemed by Christ, destined for resurrection. The flesh is the pattern of desire, habit, and orientation shaped by years of sin and still pulling against the Spirit's work.
The Works of the Flesh
Paul lists the works of the flesh in Galatians 5:19-21: sexual immorality, impurity, sensuality, idolatry, sorcery, enmity, strife, jealousy, fits of anger, rivalries, dissensions, divisions, envy, drunkenness, carousing. The list is notably not just "obviously sinful" behaviours — it includes the relational sins (enmity, strife, jealousy, divisions) that are just as much works of the flesh as the more dramatic ones.
The Path to Victory
Crucifixion, not management. "Those who belong to Christ Jesus have crucified the flesh with its passions and desires." (Galatians 5:24). The cross is the decisive act — the flesh is not to be managed or moderated but put to death. This is the language of mortification — the daily, deliberate killing of sinful patterns.
Walking in the Spirit. "But I say, walk by the Spirit, and you will not gratify the desires of the flesh." (Galatians 5:16). The positive side: the Spirit-filled life crowds out the flesh. The solution is not primarily negative (don't do this) but positive (walk in the Spirit).
Putting on Christ. Romans 13:14: "Put on the Lord Jesus Christ, and make no provision for the flesh." No provision — cutting off the supply lines of sinful desire.