According to the Book of Acts and other sources, Paul was working in Ephesus for two years (Acts 19:10) and many miracles took place, including expelling demons. Others wanted to imitate Paul and got themselves into troubles (cf. Acts 19:13–20).
We need to realize that we have a powerful enemy that wants to snatch us away from God. On our own we cannot stand up against it, we need God’s help (1:19–23; 2:1–7; 4:7–10; 5:7–14, 17).
6:10 - we are called to be strong but not with our own strength but with the strength of the Lord. This is very important point (see 1 Sam. 30:6). It is the Lord who provides the power.
6:11 To be strong in the Lord (v. 10) the Christian must “put on” (cf. 1 Thess. 5:8) the full armor that is God’s. He supplies it for the believer (cf. Isa. 11:5; 59:17).
Here, we have two interesting point. (1) we are strong because of the Lord’s strength and (2) we need to accept the armor of God. God provides us with everything - are we willing to accept it or shall we battle with our own strength and armor and fail?
Another reminder is the “wiles of the devil” (see Gen 3:1 for the description of Satan - extremely crafty).
Perhaps, In the context of this epistle the aim of Satan in view primarily has been the disunity of the body of Christ. However what Paul said here doubtless applies to all of Satan’s aims and attacks. These offensives come to us from a very intelligent and experienced strategist, and they are frequently deceptive (cf. 4:14).
From other Scripture we know that Satan is behind many of our temptations, having received permission to assail us from God (e.g., Job 1—2). He uses the world system and our flesh (sinful nature) as his tools. He also attacks us directly himself and through his angelic emissaries. God has given us specific instruction in Scripture about how to combat these attacks. We are to resist the devil (1 Peter 5:8–9), flee the temptations of the world system (the lust of the flesh, the lust of the eyes, and the pride of life; 1 John 2:15–17; 1 Tim. 6:11; 2 Tim. 2:22), and deny the flesh (Rom. 6:12–13; 7:18–24; 8:13). How do we know the source of a given temptation so we can respond to it appropriately?
6:12
This struggle does not take place on the physical level primarily, though saying no to certain temptations may involve certain physical behavior. It is essentially warfare on the spiritual level with an enemy that we cannot see. This enemy is Satan and his hosts as well as the philosophies and feelings he promotes that people implement.
“Rulers” stresses their authority and “powers” or “authorities” their strength. “World forces of this darkness” or “powers of this dark world” point to their wide influence in the world, and forces “of wickedness” or “spiritual forces of evil” relate to their evil character. They operate in the heavenly realms (1:3, 20; 2:6; 3:10).
6:13 This verse summarizes what has just preceded. We have to be ready for the unexpected. Our enemy is a great strategist and he first check our weak points. Then, it will attack. If we are not covered with God’s armor, we are totally unprotected.
6:14 This verse begins the eighth long sentence in this epistle, and it runs through verse 20 (cf. 1:3–14, 15–23; 2:1–7; 3:1–13, 14–19; 4:1–7, 11–16). The main verbs in this sentence are “stand” (v. 14) and “take” (v. 17). They are imperatives denoting urgency (cf. vv. 11, 13). Four participles follow in verses 14–16 that describe how to stand.
Isaiah described God as a soldier (cf. Isa. 11:5; 59:17; 52:7; 49:2).
Truth. The “truth” could refer to both God’s revealed truth that the Christian has believed and the Christian’s own truthfulness, specifically a lifestyle that reflects the truth.
Righteousness. Righteous conduct seems to be in view as well as the righteousness of Christ that becomes ours at regeneration.
6:15 (Is 52:7) We must be so familiar with the gospel that we can share it with others (cf. 1 Pet. 3:15). That grip on the gospel will enable us to hold our ground and even advance when tempted. The gospel in view is the whole Christian message viewed as good news.
6:16 Faith as shield. It provides a defense for the Christian in his or her spiritual warfare is two-fold. It is trust in all that God has revealed and active application of that trust at the moment of spiritual attack.
The first three participles that explain how to stand fast are “having girded” or “buckled” (v. 14), “having put on” or “in place” (v. 14), and “having shod” or “fitted” (v. 15). The fourth participle is “taking up” or “take up” (v. 16).
6:17 The second main verb in this long sentence (vv. 14–20) is “take” or, better, “receive” or “accept” (Gr. dexasthe). In addition to standing firm, having received and having already put on four pieces of armor, we also need to receive and put on two more.
Helmet of salvation. This salvation is evidently similar to a helmet because deliverance involves a mental choice, namely, trust in God rather than self, and obedience to Him. Confidence in God becomes our salvation and so protects our thinking when we are under attack.
We receive this present salvation (deliverance) as we receive all salvation, namely, by calling on God and requesting it (cf. 1:15–23; Joel 2:32; Acts 2:21; Rom. 10:13).
The word of God is similar to this short sword for the Christian. It is the appropriate Scripture spoken or put to use by the Christian in a given instance of temptation that is in view (e.g., Matt. 4:4, 6, 10).
The Holy Spirit both gives the word and empowers it as we use it. It is His sword (cf. Isa. 49:2).
6:18 Prayer and alertness (two participles in the Greek text) describe how we should “receive” present salvation and use the word appropriate to our trial. We should be in constant prayer in preparation for our spiritual battles and as we engage our enemy (cf. Mark 14:34–38; Col. 4:2). The Spirit prays for us (Rom. 8:26) and enables us to pray, as He enables us to do everything else.
In addition to praying for ourselves, we also need to pray for other Christians, who also battle against the same enemy.
The great need for prayer that exists is obvious in Paul’s use of the word “all” four times in this verse (cf. 1 Tim. 2:1).
6:19–20 Paul sensed his own great need for the prayer support of his readers. It was incongruous that an ambassador of Christ should be in chains. He was in heavenly places, but he was also in earthly confinement. An encounter with spiritual enemies awaited him when he would make his defense before Caesar Nero. Paul wanted utterance and boldness to characterize his witness.
Utterance probably refers to clarity of communication and boldness to courage. He needed bold utterance and courageous clarity in all of his ministry opportunities, but especially in the defense he anticipated in the imperial court (cf. Acts 28:30–31).
There are nine references in Acts alone to various people witnessing boldly (Acts 4:13, 29, 31; 9:27–29; 14:3; 18:26; 19:8; 13:46) plus others elsewhere in the New Testament (cf. 2 Cor. 3:12).
The mystery of the gospel (i.e., God’s provision of salvation through Jesus Christ) needed defending in Rome because the Romans viewed Christianity as simply a sect within Judaism (cf. Acts 18:12–17). The Jews saw it as a heretical religion (cf. Acts 21:27–28).
Paul’s anticipation of his defense before Nero brought him back to the present in his thinking. His exposition of the mystery of the church to his readers had ended. He had also explained their proper conduct in view of their calling. All that remained was to share with them some personal information and to pray God’s blessing on them.
6:21–22 Tychicus (lit. Chance) accompanied this letter to Ephesus and may have carried it. What Paul wrote about Tychicus and his purpose in sending Tychicus to Ephesus was almost identical to what he wrote in Colossians 4:7–8.
Tychicus’ mission was to give the Ephesian Christians further information about Paul and to comfort and encourage them (cf. Acts 20:4; Col. 4:7; Titus 3:12; 2 Tim. 4:12).
6:23 Peace, love, and faith are all important communal virtues in the Christian life. Peace was necessary because of the Jewish Gentile problems Paul wrote Ephesians to ameliorate (2:14–16; 3:15, 19; 4:3). Mutual love is the key to peace (1:15; 3:17–18; 4:2, 16), and mutual love rests on a common faith (1:15; 3:17; 4:5; cf. Gal. 5:6). The ultimate source of all three of these essential qualities is God and Jesus Christ, united here in perfect equality.
6:24 As the apostle opened his epistle by referring to God’s grace, so he ended it (1:2). God’s grace was the key to the calling of the Christian and the creation of the church. It is also essential to the conduct of the Christian (cf. 1:7; 2:5, 7–8; 3:2, 8; 4:7). Paul wished God’s unmerited favor and divine enablement on all who love Jesus Christ purely, without wrong motives or secret disloyalties (cf. 1 Cor. 16:22). As God has poured out His grace to us in all purity, so we should pour out our love to Him in purity.