Ephesians 6:16

“In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one.”

Where it comes from

Near the end of his letter, Paul describes the armor of God piece by piece: belt, breastplate, shoes, shield, helmet, sword. Roman soldiers soaked their large shields in water so that flaming arrows would hit and go out. Paul's readers knew exactly what he meant.

What it means

Of all the pieces, the shield is the one you lift. Armor you put on once; a shield you have to raise, every time, in the direction the attack is coming from. Faith works the same way. It is not a feeling you wait to have. It is a decision to hold up what you know about God against what you are being told about yourself. The darts still fly. They just stop burning.