The New Testament speaks often about the conflict between the flesh and the spirit. Sometimes the issue is complicated because it is not clear whether the human spirit is in view or God’s Holy Spirit. Sometimes the contrast is between the body with all of its physical limitations and the immaterial part of a person, but often it is between the body’s connection to the temporal world and the immaterial human spirit that has been brought to life by God’s Spirit.
When Jesus wanted His disciples to pray with Him in the Garden of Gethsemane before His crucifixion, they kept falling asleep. Jesus warned them, “The spirit is willing, but the flesh is weak” (Matthew 26:14). People are normally dominated by the body and the temporal, physical world.
Jesus told Nicodemus, “Flesh gives birth to flesh, but the Spirit gives birth to spirit” (John 3:6). A person can be alive physically (in the body or the flesh) but dead spiritually. A person who has been born again by God’s Spirit is made alive spiritually (see Ephesians 2:1 and Colossians 2:13).
In Romans 8, Paul contrasts those who live by the flesh with those who live by the Spirit. It is clear from the context that he is not referring to fleshly Christians and spiritual Christians but rather to those who have been born again by the Holy Spirit and those who have not. Paul says this explicitly in verse 9: “You, however, are not in the realm of the flesh but are in the realm of the Spirit, if indeed the Spirit of God lives in you. And if anyone does not have the Spirit of Christ, they do not belong to Christ.” Christians are described as “those who do not live according to the flesh but according to the spirit” (verse 4). Those who are in the flesh are hostile toward God, cannot submit to God, and cannot please God (verses 7–8). This can only describe unbelievers.
Paul elaborates on the conflict of flesh vs. spirit more extensively than any other New Testament writer. In Paul’s writings, the flesh stands for the natural desires of a person operating apart from God. A person who has not been raised to life spiritually is still “in the flesh.” To Paul, a person who is spiritual is one who has been born by the Spirit, even if that person will occasionally fail to live up to that reality. He warns the Galatians, “Are you so foolish? After beginning by means of the Spirit, are you now trying to finish by means of the flesh?” (Galatians 3:3).
Once the spirit of a person has been raised to life by the Spirit of God, the old desires of the flesh do not immediately disappear. There is a battle that rages on. “So I say, walk by the Spirit, and you will not gratify the desires of the flesh. For the flesh desires what is contrary to the Spirit, and the Spirit what is contrary to the flesh. They are in conflict with each other, so that you are not to do whatever you want” (Galatians 5:16–17).
The person who has been brought to spiritual life—the work of the Holy Spirit within—will want to please God. But the pull of the world and temporal, physical needs and pleasures are still present. Therefore, the Christian must feed on spiritual food and continually yield to God’s Spirit on a day-by-day, minute-by-minute basis. Feeding the spirit and yielding to the Spirit are done by reading, studying, and obeying God’s Word and then availing oneself of all of the means of spiritual nourishment that the Word prescribes, such as prayer and fellowship. The more one gets into the Word, the more he or she will desire what God desires. The more a person gets into “the world,” the more he or she will desire what “the world” desires. Although Paul does not use the flesh vs. spirit motif in Colossians 3:1–2, the verses do present the same idea: “Since, then, you have been raised with Christ, set your hearts on things above, where Christ is seated at the right hand of God. Set your minds on things above, not on earthly things.”
The strength of the Christian’s spirit’s alignment with God’s Spirit is in direct correlation to what the Christian chooses to focus on. A focus on God’s Word will cause a person to see things from His perspective and react in ways that please God. A focus on popular culture, worldly philosophy, and conventional wisdom will inevitably cause one to take the perspective of “the flesh” and will subtly or not so subtly warp his or her judgment. Living in the world, we are constantly bombarded with the values and desires of the flesh. Unless we take steps to counteract those messages, we will find ourselves out of step with the Spirit of God who lives within us.