1You were made alive when you were dead in transgressions and sins, 2in which you once walked according to the course of this world, according to the prince of the power of the air, the spirit who now works in the children of disobedience. 3We also all once lived among them in the lusts of our flesh, doing the desires of the flesh and of the mind, and were by nature children of wrath, even as the rest. 4But God, being rich in mercy, for his great love with which he loved us, 5even when we were dead through our trespasses, made us alive together with Christ—by grace you have been saved— 6and raised us up with him, and made us to sit with him in the heavenly places in Christ Jesus, 7that in the ages to come he might show the exceeding riches of his grace in kindness toward us in Christ Jesus; 8for by grace you have been saved through faith, and that not of yourselves; it is the gift of God, 9not of works, that no one would boast. 10For we are his workmanship, created in Christ Jesus for good works, which God prepared before that we would walk in them.
11Therefore remember that once you, the Gentiles in the flesh, who are called “uncircumcision” by that which is called “circumcision” (in the flesh, made by hands), 12that you were at that time separate from Christ, alienated from the commonwealth of Israel, and strangers from the covenants of the promise, having no hope and without God in the world. 13But now in Christ Jesus you who once were far off are made near in the blood of Christ. 14For he is our peace, who made both one, and broke down the middle wall of separation, 15having abolished in his flesh the hostility, the law of commandments contained in ordinances, that he might create in himself one new man of the two, making peace, 16and might reconcile them both in one body to God through the cross, having killed the hostility through it. 17He came and preached peace to you who were far off and to those who were near. 18For through him we both have our access in one Spirit to the Father. 19So then you are no longer strangers and foreigners, but you are fellow citizens with the saints and of the household of God, 20being built on the foundation of the apostles and prophets, Christ Jesus himself being the chief cornerstone; 21in whom the whole building, fitted together, grows into a holy temple in the Lord; 22in whom you also are built together for a habitation of God in the Spirit.
Paul’s moral instructions to the Ephesian believers form a major part of the letter to the Ephesians, beginning at Eph 4:1 and extending to 6:20. The problem confronted by Paul as Apostle to the Gentiles was that many of his converts, coming from a pagan background and lifestyle, did not understand what was expected of them as followers of Jesus Christ. Some apparently continued to behave in ways characteristic of their pagan background, as seen in Eph 4:25-32.
(This would not have been the case with Jewish converts, who would at least have been familiar with God’s moral and ethical expectations based on the Old Testament, even if they had difficulty keeping the law.) However, it is important to note several things: (1) Paul firmly rejected the idea, represented by the so-called “Judaizers,” that for Gentiles conversion to Christianity was a two-step process, first becoming a full Jewish proselyte (including male circumcision) and second becoming a follower of Jesus Christ. Paul held that Gentiles could remain Gentiles and become Christians directly without becoming Jewish proselytes first (and was supported in this by the decision of the Jerusalem Council, Acts 15:1-29). (2) Paul argued that Gentile converts were expected to change their former pagan behavior when they became Christians (for example, Eph 4:25-32), but he did not make this a precondition for conversion (see Eph 2:8-9). Paul’s exhortation is essentially “Live this way because you are a Christian,” not “Live this way so that you may become a Christian.” Thus most of the second half of the letter to the Ephesians is introduced by Eph 4:1: “Therefore I…exhort you to live in a manner worthy of the calling with which you were called.”