In Galatians 5, Paul makes the statement "Walk by the Spirit, and you will not carry out the desire of the flesh." It sounds so simple, but what does it actually mean?

Whenever you see spirit and flesh set side by side in a passage (“the spirit is willing, but the flesh is weak” or “the spirit wars against the flesh,” as Paul says here), we’re talking about, not the warfare between the physical body of man and his internal, mental, or spiritual inclinations, but rather the conflict that every Christian experiences between his old nature—his fallen nature, which is corrupt and is filled with desires that are not pleasing to God—and the new nature within him that has been brought to pass by the indwelling power of the Holy Spirit. Now, life becomes complicated once we are renewed by the Holy Spirit (when we become a Christian); now we have two principles at war within ourselves: the old inclinations and the new inclinations. The old inclination is against God, and the new inclination is to obey God and to do that which is pleasing to him. In this Galatians passage, Paul discusses the ongoing battle that all Christians experience. He admonishes us at one point and says, “Follow the new principle; follow the new spirit, not the old pattern that was characteristic of your original state of fallenness.” He’s not saying that your physical body is at war with your soul, but that your natural inclinations are at war with the transformation toward which the Holy Spirit is constantly moving you as a child of God. And that does involve a decision and an act of the will.

©1996 by R.C. Sproul. Used by permission of Tyndale.
Scripture taken from the New King James Version®. ©1982 by Thomas Nelson.
Used by permission. All rights reserved.