John Calvin Commentary Ephesians 6:16

"withal taking up the shield of faith, wherewith ye shall be able to quench all the fiery darts of the evil [one]." — Ephesians 6:16 (ASV)

Taking the shield of faith. Though faith and the word of God are one, yet Paul assigns to them two distinct offices. I call them one because the word is the object of faith and cannot be applied to our use except by faith; just as faith, in turn, is nothing and can do nothing without the word. But Paul, neglecting so subtle a distinction, allowed himself to speak at length on the military armor. In the first Epistle to the Thessalonians, he gives both to faith and to love the name of a breastplate, — putting on the breastplate of faith and love, (1 Thessalonians 5:8). All that was intended, therefore, was obviously this, — “He who possesses the excellencies of character which are here described is protected on every side.”

And yet it is not without reason that the most necessary instruments of warfare — a sword and a shield — are compared to faith and to the word of God. In the spiritual combat, these two hold the highest rank. By faith we repel all the attacks of the devil, and by the word of God the enemy himself is slain. If the word of God is effective in us through faith, we will be more than sufficiently armed both for opposing the enemy and for putting him to flight. And what should we say of those who take from a Christian people the word of God? Do they not rob them of the necessary armor and leave them to perish without a struggle? There is no one of any rank who is not bound to be a soldier of Christ. But if we enter the field unarmed, if we lack our sword, how can we sustain that character?

Wherewith ye shall be able to quench all the darts. But quench appears not to be the proper word. Why did he not use, instead of it, ward off or shake off, or some such word? Quench is far more expressive, for it is adapted to the epithet applied to darts. The darts of Satan are not only sharp and penetrating, but — what makes them more destructive — they are fiery. Faith will be found capable, not only of blunting their edge, but of quenching their heat.

This, says John, is the victory that overcometh the world, even our faith (1 John 5:4).