Eph. 6:10-24
Intro
A. Know God is your Ally and Satan your enemy (6:10–12).
B. Put on the armor God supplies (6:13–17).
C. Pray for boldness for Christian leaders (6:18–20).
But although Paul borrows his language from the Old Testament, the image Paul’s words in this paragraph would have evoked for most of his readers is that of a Roman soldier ready to do battle. Most adults who heard his letter read would have seen Roman soldiers and could relate this image to their spiritual warfare against the demonic powers at work in the world; God who fought for them had supplied them his armor.
Paul omits some pieces of the Roman soldier’s armor in his description; for instance, since he mentions only one offensive weapon, he uses the sword but omits the lance (the pilum). Paul probably has no particular purpose in correlating specific strengths of the Christian with specific armor body parts (cf. 1 Thess 5:8); rather, he wants his readers to know that they need all of them to be victorious.
in both Daniel and Paul the battle was fought by prayerfully submitting to God and doing his will, not by directly addressing the hostile powers (Dan 10:12–13, 21)
The “belt” or “girdle” may refer to the leather apron beneath the armor or to the metal belt protecting the lower abdomen. The “breastplate” normally consisted of leather overlaid with metal, and it protected the chest in battle; like the helmet (6:17), it was used only in battle, not for normal wear. Roman soldiers were to face forward in battle, side by side, so the armor needed to protect only their front.
Roman soldiers were equipped with large rectangular wooden shields, four feet high, the fronts of which were made of leather. Before battles in which flaming arrows might be fired, the leather would be wetted to quench any fiery darts launched against them. After Roman legionaries closed ranks, the front row holding shields forward and those behind them holding shields above them, they were virtually invulnerable to any attack from flaming arrows.
The sword (gladius, 20–24 inches long) was a weapon used when close battle was joined with the enemy and the heavy pikes that frontline soldiers carried were no longer practical. Thus Paul implies that the battle is to be joined especially by engaging those who do not know God’s word (the gospel) with its message, after one is spiritually prepared in the other ways listed here. Paul’s ministry was thus particularly strategic, because it included close-range battle advancing into enemy ranks
6:18–19. If prayer for one another (v. 18) continues the figurative image of warfare in the preceding context, it might relate to how the soldiers had to stand together in their battle formation, covering one another by moving as a solid unit. A Roman soldier by himself was vulnerable, but as a unified army a Roman legion was virtually invincible.
People cannot strengthen themselves; they must be empowered, and that not once for all but constantly, as the tense of the Greek indicates. Furthermore, he says, not ‘by the Lord’, though that would be true enough, but again in the Lord. When life is lived in union with him, within the orbit of his will and so of his grace, there need not be failure due to powerlessness