What does the Bible say about the conflict within believers?

The Bible illustrates the internal conflict in believers through the metaphor of two armies—one representing the sinful flesh and the other the new divine nature created within. As Paul writes in Romans 7, believers experience a wretched struggle: 'For I know that in me, that is in my flesh, dwelleth no good thing.' This battle is not present in the unbeliever, but for those who are regenerated, it highlights their new identity in Christ, a reality echoed in Galatians where Paul urges to 'Walk in the Spirit, and ye shall not fulfill the lust of the flesh.' The struggle serves as a reminder that salvation and perseverance are entirely by God's grace.