The believer fights valiantly against evil using the protective armor described in Ephesians 6:11-18. God provides each piece of equipment that enables us to fight the cunning attacks of Satan at our weakest points. JTL17 13.1
The girdle with which the soldier binds himself is truth, not just personal honesty but the truth about God and His character. This truth must not only lodge in our hearts, but we must act on it! The breastplate represents the righteousness of Jesus which preserves the spiritual life of the believer, and without which we can never see God. The footwear represents the sandals of the soldier which enables him to stand his ground with sure footing. Because he has the “gospel of peace” (v. 15), representing the assurance of salvation through Christ, the soldier can stand firmly in peace during a spiritual conflict, but also be prepared to carry the Good News of salvation through Christ (Romans 10:15). JTL17 13.2
The shield represents faith, which “is the victory that overcometh the world” (1 John 5:4). It’s faith that stops the arrows of temptation before they become sin. The “fiery darts” (v.16) can be fear, discouragement, anger, unholy thoughts, envy, jealousy, or any other temptation of Satan. The “helmet of salvation” (v.17) protects the assurance of redemption in the mind and intellect of the believer. The sword of the Spirit is the Word of God that cuts through every deception with which Satan tries to ensnare us. JTL17 13.3