What does the Bible say about the battle not being ours?

The concept that 'the battle is not yours, but God's' is rooted primarily in 2 Chronicles 20:15. In this passage, King Jehoshaphat faces a daunting enemy and realizes that human efforts are futile in the face of overwhelming odds. Instead, he turns to the Lord in humility and seeks divine assistance. This reflects a broader biblical theme that acknowledges God’s sovereignty in all affairs, including our personal struggles against sin. The story demonstrates that believers, unlike those outside of faith, can engage in the true battle against sin, knowing that ultimate victory is determined by God’s grace and intervention.