For we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places. 13 Therefore take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand firm. —Ephesians 6:12-13
Verse 12 in this passage takes us a step further in providing a ground to this purposeful command in Ephesians 6:11. The reason for this armor of God is that our battle is not stuck in the human realm. That difficult patch at work, that continual point of argument with your spouse, that negative family member who belittles your faith—flesh and blood are not really the issue. It’s actually the cosmic powers over this present darkness.
You’re in hand-to-hand combat. You’re grappling for faith, putting your own grueling sweat up against these demonic powers. Paul is clear: we are wrestling against them.
And it is exactly because of this that we need the whole armor of God. We are wrestling, therefore we need his armor.
And the point of God’s armor is that we would be able to stand firm. Though our faith is assaulted and its flame constantly doused by the enemy, by God’s armor we will persevere and stand through it all. It’s like the scene in Pilgrim’s Progress when Interpreter shows Christian the burning fire.
Then I saw in my dream that the Interpreter took Christian by the hand, and led him into a place where was a fire burning against a wall, and one standing by it always, casting much water upon it to quench it: yet did the fire burn higher and hotter. . .
The fire kept burning. Christian remained standing.
Interpreter tells us about the one who incessantly pours oil on the fire to keep it alive. He explains:
This is Christ, who continually, with the oil of his grace, maintains the work already begun in the heart; by the means of which, notwithstanding what the devil can do, the souls of his people prove gracious still (John Bunyan, The Pilgrim’s Progress, 75ff).
That is, the souls of his people stand firm.