What does the Bible say about spiritual warfare for believers?

The Apostle Paul describes the internal struggle of believers in Romans 7:14-25, highlighting the war between the spiritual and carnal natures. He acknowledges that while the law of God is good and spiritual, he, in his flesh, is carnal and sold under sin. This conflict results in Paul doing what he hates while finding delight in the law of God after the inward man. Every believer experiences this warfare as they battle against the fleshly desires while striving to live in accordance with God's will. This struggle serves as a reminder of our dependence on Christ, who ultimately delivers us from this body of death.