What does the Bible say about the battle between the spirit and the flesh?

In Galatians 4:29, it is indicated that just as the one born of the flesh persecuted the one born of the Spirit, believers will face conflicts with their sinful nature after being born again. The battle with the flesh represents spiritual warfare that begins post-salvation. This teaching also reflects the trials the Israelites encountered with Amalek after their deliverance from Egypt—symbolically representing the flesh that remains in believers after their redemption. This ongoing warfare signifies the struggle every believer faces, emphasizing reliance on Christ for victory.