Theologians who speak of the struggle to come to spiritual maturity and to follow Christ usually speak of three main enemies to the Christian. Having looked at the first of these foes — the world, the sinful customs and traditions of humanity (1 John 2:15) — we will now look at our second major enemy, which is the flesh. Today’s passage is one of many places in the New Testament where the apostles discuss the conflict between the flesh and the Spirit, exhorting us to live by the Spirit and not the fleshly, fallen Adamic nature with which we are born.
We should first note that the term flesh in this passage does not refer to the physical body in itself. Although Scripture can use that word to refer to our physicality, the biblical writers often prefer it as a designation for indwelling sin, that part of us that remains opposed to the Lord and against which we struggle until our glorification. Unlike the tradition of many ancient Greek philosophers, there is no place in Christianity for the belief that matter is inherently evil. It may be fallen, but the Bible teaches that the physical world is a good thing in and of itself (Gen. 1:31). In fact, the physical world is so important that the Lord is including it in His redemption of all things. A new heaven and earth is coming, a realm that is no less significant than the invisible realm of heavenly beings (Isa. 65:17–25).
Thus, the war between flesh and spirit depicted in Scripture is not a war between body and soul but rather a war within ourselves — a war of our desires. We have new life from the Spirit, and our remaining sin, that part of our Adamic heritage that we have not yet fully cast aside, hates this new life (John 3:1–8; Rom. 7:7–25; Eph. 4:17–24). Of course, having trusted in Christ alone, we have been set free from enslavement to sin and enabled to live according to His commandments. Our sinful flesh, however, remains present until we are glorified, and until then it rises up and strives to quench and grieve the Holy Spirit’s influence (Eph. 4:30; 1 John 1:8–9).
Until we are glorified, we are commanded to put our fleshly nature to death so that we will keep in step with the Spirit (Col. 3:5). This is achieved through taking up God’s armor against our flesh. And through the defeat of the flesh, we defeat the Devil, who entices our flesh to rise up against the Lord (Eph. 6:10–20).