The whole armor of God is an image that is pretty familiar to us.
“Finally, my brethren, be strong in the Lord, and in the power of his might. Put on the whole armour of God, that ye may be able to stand against the wiles of the devil. For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places. Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand. Stand therefore, having your loins girt about with truth, and having on the breastplate of righteousness; And your feet shod with the preparation of the gospel of peace; Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked. And take the helmet of salvation, and the sword of the Spirit, which is the word of God: Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints; And for me, that utterance may be given unto me, that I may open my mouth boldly, to make known the mystery of the gospel, for which I am an ambassador in bonds: that therein I may speak boldly, as I ought to speak” (Eph. 6:10-20).
But perhaps we may draw a few new observations from a passage that is well-known to us. The first thing to note is that the whole armor of God is God. The armor is personal. We are told to be strong in the Lord. The breastplate is righteousness; the Lord is our righteousness (Jer. 23:6). Our feet are shod with the preparation of the gospel of peace. The Lord is the prince of peace (Is. 9:6). Our shield is faith; the Lord is faithful (1 Cor. 1:9). The helmet is salvation; the Lord is our salvation (Ps. 27:1). The sword of the Spirit is the word of God, and of course, the word of God is living and active (Heb. 4:12).
The second thing is that Paul is drawing on the language of Isaiah. On the assumption that he is doing so for a reason, we should draw certain conclusions about the nature of our spiritual warfare.
“And the Lord saw it, and it displeased him that there was no judgment. And he saw that there was no man, and wondered that there was no intercessor: Therefore his arm brought salvation unto him; and his righteousness, it sustained him. For he put on righteousness as a breastplate, and an helmet of salvation upon his head; and he put on the garments of vengeance for clothing, and was clad with zeal as a cloke. According to their deeds, accordingly he will repay, fury to his adversaries, recompence to his enemies; To the islands he will repay recompence. So shall they fear the name of the Lord from the west, and his glory from the rising of the sun. When the enemy shall come in like a flood, the Spirit of the Lord shall lift up a standard against him. And the Redeemer shall come to Zion, and unto them that turn from transgression in Jacob, saith the Lord. As for me, this is my covenant with them, saith the Lord; My spirit that is upon thee, and my words which I have put in thy mouth, shall not depart out of thy mouth, Nor out of the mouth of thy seed, nor out of the mouth of thy seed’s seed, saith the Lord, from henceforth and for ever” (Is. 59:15-21).
Consistent with the first point we made, notice that the Lord is the one who puts on this armor. He puts on the breastplate of righteousness. He puts on the helmet of salvation. He is not climbing into the escape pod of salvation, which means that something other than radical individualism is going on. Salvation is the helmet worn by the Savior, which means that when we put it on, we are not so much indicating that we are “saved” (although we have been), but that we have been enlisted in Christ’s army of saviors.
In Ephesians, the battle is against principalities and powers, and here in Isaiah it is against “enemies.” Comparing the two passages together, we can see that the fight is not principally with nonbelievers, but is rather over nonbelievers. When we are dressed out in the armor, what then? We go to war by going to prayer, and the prayer involves asking on behalf of “all the saints” and for Paul’s boldness in preaching the gospel.
One last thing. Notice how many elements of our armor are found in Psalm 85.
“Lord, thou hast been Favourable unto thy land: Thou hast brought back the captivity of Jacob. Thou hast forgiven the iniquity of thy people, Thou hast covered all their sin. Selah. Thou hast taken away all thy wrath: Thou hast turned thyself from the fierceness of thine anger. Turn us, O God of our salvation, and cause thine anger toward us to cease. Wilt thou be angry with us for ever? Wilt thou draw out thine anger to all generations? Wilt thou not revive us again: That thy people may rejoice in thee? Shew us thy mercy, O Lord, And grant us thy salvation. I will hear what God the Lord will speak: For he will speak peace unto his people, and to his saints: But let them not turn again to folly. Surely his salvation is nigh them that fear him; That glory may dwell in our land. Mercy and truth are met together; Righteousness and peace have kissed each other. Truth shall spring out of the earth; And righteousness shall look down from heaven. Yea, the Lord shall give that which is good; And our land shall yield her increase. Righteousness shall go before him; and shall set us in the way of his steps” (Ps. 85:1-13).