3 I got the inside story on this from God himself, as I just wrote you in brief. 4 As you read over what I have written to you, you'll be able to see for yourselves into the mystery of Christ. 5 None of our ancestors understood this. Only in our time has it been made clear by God's Spirit through his holy apostles and prophets of this new order. 6 The mystery is that people who have never heard of God and those who have heard of him all their lives (what I've been calling outsiders and insiders) stand on the same ground before God. They get the same offer, same help, same promises in Christ Jesus. The Message is accessible and welcoming to everyone, across the board.
Matthew Henry's Commentary on Ephesians 3:3-6
Commentary on Ephesians 3:1-7
(Read Ephesians 3:1-7)
For having preached the doctrine of truth, the apostle was a prisoner, but a prisoner of Jesus Christ; the object of special protection and care, while thus suffering for him. All the gracious offers of the gospel, and the joyful tidings it contains, come from the rich grace of God; it is the great means by which the Spirit works grace in the souls of men. The mystery, is that secret, hidden purpose of salvation through Christ. This was not so fully and clearly shown in the ages before Christ, as unto the prophets of the New Testament. This was the great truth made known to the apostle, that God would call the Gentiles to salvation by faith in Christ. An effectual working of Divine power attends the gifts of Divine grace. As God appointed Paul to the office, so he qualified him for it.