Ephesians 6:10–13, “10 Finally, be strong in the Lord and in the strength of his might. 11 Put on the whole armor of God, that you may be able to stand against the schemes of the devil. 12 For we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places. 13 Therefore take up the whole armor of God, that you may be able to withstand in the evil day, and having done all, to stand firm.”

After unfolding the implications of the gospel for several different relationships (Eph. 5:22–6:9), Paul in Ephesians 6:10–20 returns to exhortations for all Christians, no matter their station in life. His teaching on God’s armor does not abruptly change topics but advances his outline of the gospel’s consequences. The Apostle’s use of the word finally in verse 10 indicates that this section is the culmination of all that he has said.

Though Ephesians was written as a summary of Christian doctrine, theological knowledge is never intended merely to satisfy our intellectual curiosity. Paul did not tell us about the gospel and the church’s purpose (Ephesians chapters 1–3), so that we could sit back and relax. Instead, he taught us these things that we might obey His will in the Spirit’s power, thereby participating in the kingdom’s expansion (Ephesians 4:1–6:9).

Unless we know the enemy we face and how to defeat him, however, our efforts to live out the gospel are for naught. Scripture lists our main enemies as the world, the flesh, and the Devil (1 John 2:15–17; Gal. 5:16; 1 Peter 5:8), all of whom are formidable indeed. Ultimately, however, to fight any of these is to fight the Enemy himself. “We do not wrestle against flesh and blood, but against … the spiritual forces of evil in the heavenly places” (Eph. 6:12). To stand against the world is to stand against the Evil One, the ruler of this fallen world (Matt. 4:8–9). To fight our sinful nature is to battle the one who introduced sin into creation (Gen. 3:1–7). And, of course, to war against the Devil is to fight Satan directly (James 4:7).

The proper equipment with which to fight the Enemy is God’s armor (Eph. 6:13). This armor could be three different things. It could be the armor God supplies to His people, for He strengthens us to live for Him (Ps. 18:31–32). It could be the armor that the Lord wears to battle His foes (Isa. 59:15b–17). Or this armor could be God Himself, as Scripture uses terms such as truth and righteousness, which we wear as armor (Eph. 6:14), to name the Lord (Jer. 23:6; John 14:6). The armor of God likely encompasses all these possibilities, for they are not mutually exclusive. God supplies us with Himself to strengthen us against Satan. Standing in Him, we can successfully live out the implications of the gospel.

John Calvin comments, “There will be no danger which may not be successfully met by the power of God; nor will any who, with [the armor of God], fight against Satan, fail in the day of battle.” Daily we are to remember our identity in Christ, putting on His graces that are ours now in Christ, and casting off the rebellious impulses that we possess in Adam. In doing so, we are guaranteed success in our spiritual conflicts and are assured of a hero’s welcome in glory.