|In addition to all this, take up the shield of faith, with which you can extinguish all the flaming arrows of the evil one.|
|Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked.|
Faith in this context is the firm confidence in the Lord and in His Word. For, "Every word of God proves true and He is a shield to all who come to Him for protection." (Proverbs 30:5)
Flaming arrows could not penetrate the fireproof shield of the Roman soldiers. Their shields were constructed in such a way to defeat this threat.
Paul tells us to protect ourselves when temptation strikes by using the shield of faith. Sin strikes when we let down our shield.