What does the Bible say about the believer's conflict?

The believer's conflict stems from the presence of two natures within every believer: the old man, which is corrupted by sin, and the new man, which is born of the Spirit. As Paul writes in Galatians 5:16-17, the flesh lusts against the Spirit, and the Spirit against the flesh, leading to an internal conflict where each believer experiences a desire to do good while also battling sinful inclinations. This struggle is foundational to the Christian experience and highlights the importance of walking in the Spirit to overcome the desires of the flesh.