Therefore, put on the armor of God, so that you will be able to hold fast on the evil day and to hold your ground with all your strength. Stand firm, then, with the belt of truth fastened around your waist, with the breastplate of righteousness clothing you.
Ephesians 6:13-14
Paul’s second letter to the Corinthians is a defense of his apostleship in the face of opposition and attacks from false apostles (2 Corinthians 11:13-15). He was in a spiritual battle, to be sure. But he made it clear that spiritual warfare is not a physical battle using the world’s weapons of war. Instead, it is a battle of thoughts, arguments, and ideas waged in the battlefield of the mind (10:3-6). That is, it is a battle for the truth.
The battle for truth began in the Garden of Eden when Satan lied to Adam and Eve, contradicting what God had told them (Genesis 3:1-5). And lies remain Satan’s chief weapon. If he can convince us to doubt God’s words, he will have weakened the foundation of our faith: the truthfulness of God and His promises. That is why when describing the Christian’s spiritual armor, Paul calls the Roman soldier’s belt the belt of truth. We are sanctified—conformed to Christ—by the truth of God’s Word (John 17:17).
Just as Jesus rebuffed Satan’s temptations with the truth of God’s Word, we must do the same (Matthew 4:1-11). Truth wins the spiritual war.