Ephesians 3:1

For this cause - Because he maintained that the Gentiles were admitted to all the privileges of the Jews, and all the blessings of the new covenant, without being obliged to submit to circumcision, the Jews persecuted him, and caused him to be imprisoned, first at Caesarea, where he was obliged to appeal to the Roman emperor, in consequence of which he was sent prisoner to Rome. See Acts 21:21-28, etc.

The prisoner of Jesus Christ for you Gentiles - For preaching the Gospel to the Gentiles, and showing that they were not bound by the law of Moses, and yet were called to be fellow citizens with the saints; for this very cause the Jews persecuted him unto bonds, and conspired his death.

For this cause - On account of preaching this doctrine; that is, the doctrine that the gospel was to be proclaimed to the Gentiles.

I Paul, the prisoner of Jesus Christ - A prisoner in the service of the Lord Jesus; or made a prisoner in his cause. Not a prisoner for crime or debt, or as a captive in war, but a captive in the service of the Redeemer. This proves that at the time of writing this, Paul was in bonds, and there can he no question that he was in Rome. This would be more correctly rendered, "For this cause I, Paul, am the prisoner," etc. So Tyndale renders it, "For this cause I, Paul, the servant of Jesus, am in bonds." So also Locke, Rosenmuller, Doddridge, Whitby, Koppe, and others understand it. By this construction the abruptness now manifest in our common version is avoided.

For you Gentiles - Made a prisoner at Rome on your behalf, because I maintained that the gospel was to be preached to the Gentiles; see Acts 22:21-23. He was taken first to Cesarea, and then to Rome. The cause of his imprisonment and of all his difficulties was, that he maintained that the gospel was to be preached to the Gentiles; that when the Jews rejected it God rejected them; and that he was specially called to carry the message of salvation to the pagan world.

3:1 For this cause - That ye may be so "built together," I am a prisoner for you gentiles - For your advantage, and for asserting your right to these blessings. This it was which so enraged the Jews against him.