Through this he again urges the listener to vigilance. The danger, he says, is in a great matter, for the issue is not about earthly and perishable things, but about heavenly ones. The preposition "in" (ἐν) is used instead of "for" and "for the sake of" (διά), as if to say: we fight for the sake of heavenly things, and therefore one must be watchful.
Eph. 6:13. For this reason take up the whole armor of God, that you may be able to withstand in the evil day
That is, in the present age, because he calls it an evil day from the evil deeds committed in it. He also encourages by pointing out that the time of struggle is brief. For, by calling it a day, he indicates its brevity.
Eph. 6:13. and, having overcome all things, to stand firm.
Having overcome all passions and shameful desires, that is, having conquered and put them to death. And since many have fallen even after victory, he says: "to stand." Even after victory, firmness is needed, so that the one defeated does not rise up in war again. For if we give ourselves over to carelessness, the slain enemy will surely come to life again. Note that it is possible both to overcome and to stand firm, and we must not afterward lose heart on the pretext that the enemies are powerful. For we have been given such strength and taught such skill that we can fight even against demons, and even more — not only fight, but be so fearsome to demons, by the power of Him who dwells in us, that we need not even struggle, but simply trample upon serpents and scorpions. Paul says this because their adversaries were many, teaching that through these people demons wage war against us. Therefore, do not be angry at people, but arm yourselves against demons.
Eph. 6:14. Stand therefore, having girded your loins with truth
In the matter of war, the first thing is to know how to stand well; therefore Paul first of all gives counsel concerning standing, requiring that it be proper, befitting soldiers — upright. For he who stands in the proper manner stands upright, not inclining toward anything, just as he who does not stand is not upright; for example, a lustful person, a lover of money, and one living luxuriously does not stand upright but inclines toward something. After the standing, he girds the soldier, of course in a spiritual sense, and the one who is dissolute and in a state of relaxation from desires, he binds together, drawing tight by means of a belt. By "loins" he means the courage of the soul and the strength that endures all things. As the keel is to ships, so the loins in living creatures constitute a kind of foundation. Therefore we too, from fatigue, often rest by placing our hands on our loins. Such also is the position of the spiritual loins, which the apostle commands to gird with truth, consisting both in doctrine and in life. For none of the heretics is girded with truth, but they revolve below, around the earth, having no ability to comprehend anything lofty, but with human thoughts that revolve downward they investigate divine things. Moreover, being unsteady in life as well, and submitting to the seductions of the world, they not only are not girded with truth but, having fallen low, even thirst for falsehood. But we must not be such, but in all things follow truth: whether it be doctrine, we must seek truth in it; whether it be life, likewise. We must be sincere, free from guile, not allowing falsehood toward one another. If we are thus girded, we shall be in a condition to press toward the goal; and by this girding he indicates that we must always be armed, as David also says: "like a belt with which he is always girded" (Ps. 108:19); for we are in unceasing war. Gregory the Theologian, however, understands by our loins the desiring faculty (for in the loins are the inward parts, which in Scripture are a symbol of desire), and by truth the contemplative faculty. Therefore he affirms that Paul here exhorts us to gird every desire of ours with contemplation and meditation upon God. For he who contemplates God and finds joy in Him as the truly Beloved will not allow his desire to turn toward anything base and revolve around earthly things.
Eph. 6:14. and having put on the breastplate of righteousness,
Here he calls righteousness the virtuous life in general, as if saying: having clad your breast with righteous deeds. For just as a breastplate makes a person invulnerable, so too does righteousness for the one who has clothed himself in it.
Eph. 6:15. And having shod your feet with the readiness of the gospel of peace;
He well proposes to us the greaves also. By this he speaks either of the need to be ready for the proclamation and preaching of the Gospel. For "beautiful," he says, "are the feet of him who announces peace" (Isa. 53:7). Or that we must be ready for our departure, living according to the Gospel. For feet are a symbol of life; therefore he also says: "walk carefully" (Eph. 5:15). And the readiness to proclaim the Gospel means good works, to which the Lord also attends, as it is said: "the preparation of their heart Thine ear hath heard" (Ps. 10:17). He also well said: "peace." Since he had mentioned war and battle, he shows that this war must be waged against demons, not against people — for the Gospel is about peace — and that in fighting against demons, we remain at peace with God, Whom we must not provoke again to war against us by breaking the peace. But the good news already is; the victory has been accomplished; therefore let us not be afraid.
Eph. 6:16. But above all, take up the shield of faith,
Above all, by the words "above all" he points to the truth and righteousness mentioned earlier, and the hope of the Gospel. For all of this requires faith. But by faith here he means not the knowledge of true worship of God, but faith free from doubt, which makes one believe in the future as though it were the present, which performs signs and is so fervent and ardent that it even moves mountains. Therefore, just as a shield covers the entire body, enclosing and protecting it like a wall, so too faith without doubt is a fortress for the entire soul. Such faith, and not mere reasoning, is a shield. A shield protects, while those only hinder.
Eph. 6:16. with which you will be able to extinguish all the fiery arrows of the evil one;
That is, shameful desires, thoughts of unbelief (such as: will there be a resurrection? will there be a judgment?) and temptations. "Fiery" not only because lusts kindle and inflame toward shameful deeds, but also because here we are, as it were, burned by our conscience. Moreover, the devil also sets us on fire both through thoughts of unbelief and through temptations. But faith extinguishes this; for if it subdues demons, then all the more so the passions. For if lust inflames you, by believing in the future blessings and joy, you will extinguish it; if temptation burns you, by believing in the future, you will find consolation. Consider with what fire Abraham was burned when he was offering his son as a sacrifice, but faith extinguished that flame.
Eph. 6:17. And take the helmet of salvation,
That is, saving and protecting. For if we have faith (saving and guarding us), then we will soon receive also salvific thoughts, guarding our head or governing mind.
Eph. 6:17. And the sword of the Spirit, which is the Word of God.
In the above, Paul armed us so that enemies would not harm us, but now he gives a weapon by which we ourselves can inflict great harm upon our enemies. So, by the sword of the Spirit he figuratively means either the Spirit Himself, or the spiritual life, by which the head of the dragon is crushed. And this spiritual sword is the word of God, that is, the commandment. For if we fulfill His commandments, we will slay the cunning serpent, as Isaiah says (Isa. 27:1). Or the word of God is the expression: "in the name of Jesus Christ, rise up and walk" (Acts 3:6), and similar ones. Or by the sword of the Spirit he simply means spiritual wisdom. "For the word of God is living and active and sharper than any sword" (Heb. 4:12), and he who possesses the gift of this spiritual sword and speaks divine things is invincible, as was Paul himself.
Eph. 6:18. With all prayer and supplication, pray at all times in the spirit,
Having armed them, he finally leads them to the King, to entreat Him to stretch out His hand. For having said, "you shall be able to quench," lest they become proud, he says: you have need of God and can accomplish the entire task together with the aforementioned prayer, praying not simply, but "with all prayer and supplication," with weeping, beating of the breast, genuflection, and similar actions. And not only at the appointed hours, but "at all times" and "in the Spirit," that is, asking for spiritual things, not worldly ones. But in saying, "pray with all prayer," he hints that it is possible even while performing prayer not to pray, when someone engages in idle talk.
Eph. 6:18. "and strive for this very thing"
Or he speaks here of all-night vigils, or of the wakefulness of the soul; both can be understood. For one who is armed and standing before the king must be watchful.
Eph. 6:18. "with all perseverance and supplication"
Prayer joined with patience is indeed such, like that of the Canaanite woman, the widow, and Anna.