The most famous passage in what is called "Spiritual Warfare" is Ephesians 6—but we have not done that text justice. In Ephesians, two themes intertwine, and are in fact one theme: 1) the astonishing unity of people groups that detested one another into the unity of the Spirit, and 2) Jesus' power over the unclean powers--flowing through the church's unity! Most popular literature treats putting on the armor as the work of a single Christian who needs to be armed against the strategies of the devil. While it is wise to be aware of the enemy's schemes as individuals, the point of Ephesians is that Jesus has smashed demonic power through our unity. This is created by the Holy Spirit, each time a believer gets saved that believer gets melded together with millions of others into a new race. This race, a whole new species of human has a unity which defies Satan's destruction of God's work. The point of the book is that no longer are we to consider ourselves merely as individuals belonging to an ethnic group, but rather we are now melded together with Jesus, who is forging a people, who together are filled with the fullness of God. It manifests itself as the unity of His people! This unity theme is the foundation for Paul's words about needing to do spiritual battle together, by maintaining the unity of the Spirit created by Jesus' death and resurrection, and our entrance into His body.
Doing this as individuals, while helpful isn't what the book is talking about.
The point is that the entire church is to put those pieces on together, at the same time, so that all of God’s people can stand against evil—TOGETHER.
To capture the intent of the previous chapters in the book, I have mixed in the metaphor of the new race, the new human (Jesus, the Second Adam) into the plural commands used in Ephesians. (He was addressing the church together, not just an individual or two). While that image isn't in the exact text of Ephesians 6, it is assumed. All the commands are plural, and they are given after a long section in which Paul requires unity at all levels of society. Here then is a combination of a paraphrase, and a translation of Ephesians 6:10-19.
Picture ten thousand soldiers, line on line, getting ready for battle. Paul the Aposlte, speaking on behalf of the Commander of God's Army, Jesus Himself, writes out and reads His orders to the buck privates, the corporals, the colonels and the Generals in turn. Here is what he says:
By way of summary, all of you, be strong in your common Lord together, as you together stand in Jesus as the New Man, a New Species of human!
Put on the armor of Jesus together, so that all of you will be able to stand as one Man, standing firmly together against the devil’s schemes.
For we together aren’t in a battle with mere humans and the evil they do…
We, as an army together, are engaged in hand to hand combat with demonic legions,
we are wrestling as a people united together against malevolent rulers,
against wicked powers,
against world forces of darkness,
against spiritual energies of wickedness in the heavenlies…
So, all of you, each apart and all together, put your armor on as one Man, so that all of you will be able to stand and resist his schemes together in the day when evil pushes hard against everything good to destroy it.
United together, you will be able to hold each other up, to stand firm together…
Having done everything to prepare together, stand your ground as One, Being in the One Man, Christ Jesus Himself!
All of you together—put your belts on to wrap your waists in truth… Jesus’ Truth!
Together now, attach the breast-shield of right-living to that belt… Jesus’ Right-Living!
Now as one New Man, prepare your feet; put on gospel-boots to walk lockstep together, each stride producing peace… Walking in step together as Jesus walked…
Now, together, interlock your shields of faith, Jesus’ faith—when they mesh together, the devil’s fiery darts get blocked and their burning is extinguished.
Now together, put your helmets on—wrap your minds around with Jesus’ mind…
All together, raise the Sword wielded by the Spirit—
Jesus, the Word, Jesus’ Spirit the Word-wielder…
Now—together, with every kind of prayer you know, pray together at all times in the Spirit, with this in mind--persevere in prayer for every believer, in any and every kind of circumstance,
and pray for me to boldly proclaim the mystery of the gospel—that mystery is the unity of the Spirit, found in Jesus…
Ephesians 6:10-19 DCV paraphrase
The greatest weapon against the Devil’s divisions
is the church united together in unity of the Spirit
