Watchman Nee explores the intricate relationship between the soul and the flesh, emphasizing that the flesh represents our sinful nature while the soul embodies our life. He explains that before salvation, the soul was driven by the flesh, leading to a life of sin. Upon receiving Christ, believers gain a new life and nature, resulting in an internal struggle between the old sinful nature and the new divine nature. This conflict can lead to instability in a believer's life, but understanding the crucifixion of the flesh allows for victory over sin. Ultimately, Nee warns that even as believers may feel spiritually advanced, they can still be trapped in a soulish state, needing continual growth in their faith.

Before we go on, we must first understand the relationship between the soul and the flesh. In the Bible, the flesh, as far as the lust of our flesh is concerned, is our sinful nature. The soul is our life. When we speak of our new life and new nature, it is as if life and nature are the same thing, but strictly speaking, there is a difference between life and nature. It seems that life involves something more than nature. Every life has its own nature. The nature is the natural principle of that life; it is the inclination and desire of the life. While we were sinners, our life was the soul and our nature was the flesh. We lived by our soul, and the inclinations and desires of our living were according to the flesh; we walked by the flesh. More simply put, it was the flesh that decided how we walked and the soul that supplied the power to walk according to that decision. The flesh, the sinful nature, gave the suggestions; and the soul, the life, supplied the power. The flesh instigated, and the soul executed. This is the condition of every unbeliever. At the time a believer receives the grace of the Lord Jesus' substitutional death on the cross, God puts His life within him and resurrects his spirit. This new life brings with it a new nature. From that point on, there are two lives within the believer, the spirit and the soul-life. There are also two natures within him, God's nature and the flesh. These two natures, one new and one old, are mutually exclusive, contradictory, and incompatible one with the other. Daily the new and the old struggle with one another, vying to rule over the whole being. A Christian who is on this level is an infant in Christ; he is fleshly. His experience at this stage is very unstable and painful, repeatedly alternating between victory and defeat. Later, he begins to realize the salvation of the cross and learns that if he believes that his flesh has been crucified with the Lord on the cross, he will overcome his sinful nature, that is, his flesh will be as silent as if it were dead and will no longer harm him. Since his flesh, the sinful nature, is crucified, he will have the power to overcome sin and will realize in his experimenting the promise that says, "Sin will not lord it over you" (Rom. 6:14). Through this, the believer will enter another realm. Sin will be under his feet. Although there will still be the passions and lusts of the flesh, they will not be able to attract him anymore. The believer will now think that he is completely spiritual. When he looks back, he will see many who believed at the same time that he believed, yet they are still bound by sin. He will be self-flattered, thinking that he has reached perfection, the highest plane of the spiritual life, and that he is fully spiritual. Actually, he is not so, but far from it. He unavoidably remains a soulish Christian.