1 Thessalonians 5:8

"But let us, since we are of the day, be sober, putting on the breastplate of faith and love; and for a helmet the hope of salvation." But it is not sufficient to watch and be sober, we must also be armed. For if a man watch and is sober, but has not arms, the robbers soon dispatch him. "Putting on the breastplate of faith and love," he says. He has shown what it is to watch and be sober, to have "the breastplate of faith and love." Not a common faith, he says, but as nothing can soon pierce through a breastplate, but it is a safe wall to the breast; so do thou also, he says, surround thy soul with faith and love, and none of the fiery darts of the devil can ever be fixed in it. For where the power of the soul is preoccupied with the armor of love, all the devices of those who plot against it are vain and ineffectual. "And for a helmet the hope of salvation." For as the helmet guards the vital part in us, surrounding the head and covering it on every side, so also this hope does not suffer the reason to falter, but sets it upright as the head, not permitting anything from without to fall upon it. And whilst nothing falls on it, neither does it slip of itself. For it is not possible that one who is fortified with such arms as these, should ever fall. For "now abideth faith, hope, love." (1 Cor. xiii. 13)