1. PUTTING ON THE ARMOR (6:10–13)
a. What: to be strong in the Lord (6:10).
6:10. Paul exhorted believers to be strong in the Lord and in the might (kratei, “power that overcomes resistance” as used in Christ’s miracles) of God’s inherent strength (ischyos; cf. “the power [kratous] of His inherent strength” [ischyos] in 1:19). Hence believers can be strengthened not only by the person of the Lord but also by His resources (cf. Phil. 4:13).
b. How: to put on God’s armor (6:11a).
6:11a. The form of the Greek imperative put on indicates that believers are responsible for putting on God’s (not their) full armor (panoplian, also in v. 13; all the armor and weapons together were called the hapla; cf. 2 Cor. 6:7) with all urgency. The detailed description of the armor (given in Eph. 6:14–17) may stem from Paul’s being tied to a Roman soldier while in prison awaiting trial (cf. Acts 28:16, 20).
c. Why: to stand against the devil’s strategy (6:11b–13)
6:11b–12. The purpose of putting on God’s armor is to be able to stand against the schemes or stratagems (methodeias, used in the NT only here and in 4:14) of the devil or adversary (cf. 4:27). Christians are not to attack Satan, or advance against him; they are only to “stand” or hold the territory Christ and His body, the church, have conquered. Without God’s armor believers will be defeated by the “schemes” of the devil which have been effective for thousands of years.
The struggle is not physical (against flesh and blood); it is a spiritual conflict against the spiritual “Mafia.” Though the ranks of satanic forces cannot be fully categorized, the first two (rulers and authorities) have already been mentioned in 1:21 and 3:10.
Paul added the powers of this dark world (cf. 2:2; 4:18; 5:8) and the spiritual forces of evil. Their sphere of activity is in the heavenly realms, the fifth occurrence of this phrase, which is mentioned in the New Testament only in 1:3, 20; 2:6; 3:10; 6:12. Satan, who is in the heavens (2:2) until he will be cast out in the middle of the Tribulation (Rev. 12:9–10), is trying to rob believers of the spiritual blessings God has given them (Eph. 1:3).
Hoehner, H. W. (1985). Ephesians. In J. F. Walvoord & R. B. Zuck (Eds.), The Bible Knowledge Commentary: An Exposition of the Scriptures (Vol. 2, pp. 642–643). Wheaton, IL: Victor Books.