The concept of crucifying the flesh comes from the apostle Paul’s words in Galatians 5:24: “Those who belong to Christ Jesus have crucified the flesh with its passions and desires.” In this verse, it’s clear that crucifying the flesh is not something done to the believer, but by the believer: “Those who belong to Christ have crucified the flesh.”
The “flesh” that must be crucified is the sin principle that exists in our fallen human nature. In this world we live in fleshly bodies, and the body, being weak (Mark 14:38), is the gateway to sin. Our bodies, though not sinful in themselves, naturally crave comfort and pleasure, and they too often succumb to temptation, producing the works of the flesh (Galatians 5:19–21). Sin entrenches itself in the flesh, which becomes dominated by iniquity of all kinds. It is the sinful passions and wayward deeds of the flesh that Christians must crucify.
In other places, Paul speaks of a crucifixion that happens to the believer through his or her union with Jesus Christ: “I have been crucified with Christ and I no longer live, but Christ lives in me” (Galatians 2:20; see also Romans 6:6). But in Galatians 5:24, it is the believer who has taken action. Crucify the flesh describes a deliberate putting to death of the old sin nature.
Paul’s instruction was inspired by Jesus Christ Himself, who said, “If anyone wants to follow after me, let him deny himself, take up his cross, and follow me” (Mark 8:34, CSB).
Take up the cross is a figure of speech closely related to crucify the flesh. Believers are to behave like a person carrying his own cross to the place of his execution. Paul follows the Lord’s words to their logical conclusion. Not only must believers pick up and carry their cross, but they must also make sure their death sentence gets carried out. Crucifying the flesh illustrates the putting to death of selfish, sinful desires.
Believers are to take their old sin nature and, figuratively speaking, nail it to the cross. We crucify the flesh through repentance of sin—by turning our backs on the old way of life, by saying no to selfish and sinful passions, and by utterly renouncing the flesh: “Do not let any part of your body become an instrument of evil to serve sin. Instead, give yourselves completely to God, for you were dead, but now you have new life. So use your whole body as an instrument to do what is right for the glory of God” (Romans 6:13, NLT).
In the ancient world, crucifixion was the vilest, most shameful form of death, reserved for the worst of criminals. Paul undoubtedly wanted his readers to understand that the flesh is not to be treated with respect, kindness, or even indifference. The carnal nature is so evil that it deserves nothing but the most dreadful of punishments. Crucifixion was also one of the most painful forms of execution. Believers should not expect to put to death the flesh without experiencing some pain and suffering.
The flesh and the spirit are in continual conflict with each other, so our daily calling as followers of Christ is to crucify the flesh: “For if you live according to the flesh, you will die; but if by the Spirit you put to death the misdeeds of the body, you will live” (Romans 8:13; see also Romans 6:11). Because we have been delivered from sin and death to new life in Jesus Christ, we are to yield ourselves to God for His good purposes and “put to death, therefore, whatever belongs to your earthly nature: sexual immorality, impurity, lust, evil desires and greed, which is idolatry” (Colossians 3:5).
To crucify the flesh is to obey the call to Christian discipleship. It means losing our life to find it in Him (Matthew 10:39). As we daily put to death the sinful nature, we begin to walk in victory over the flesh. Conquering the flesh is what Paul describes as walking in the Spirit: “So I say, walk by the Spirit, and you will not gratify the desires of the flesh” (Galatians 5:16).