The Bible speaks of our 'spiritual warfare'-the battles we have against our own natures and against those who are opposed to the gospel of Christ:

"For though we live in the world, we do not wage war as the world does. The weapons we fight with are not the weapons of the world. On the contrary, they have divine power to demolish strongholds. We demolish arguments and every pretension that sets itself up against the knowledge of God, and we take captive every thought to make it obedient to Christ." (2 Corinthians 10:3-5).