That the Gentiles should be fellowheirs, and of the same body, and partakers of his promise in Christ by the gospel:

People's New Testament

3:6 That. The mystery long hidden, but at last revealed, is now given.

The Gentiles should be fellow-heirs. The wall of partition broken down, Jews and Gentiles equally received, heirs alike of the gospel, fellow-members of the church, fellow-partakers of the gospel promises. Compare Ac 10:34 11:18 13:46-48.

Wesley's Notes

3:6 That the gentiles are joint - heirs - Of God. And of the same body - Under Christ the head. And joint - partakers of his promise - The communion of the Holy Ghost.

Scofield Reference Notes

[1] That the Gentiles

That the Gentiles were to be saved was no mystery Rom 9:24-33 Rom 10:19-21. The mystery "hid in God" was the divine purpose to make of Jew and Gentile a wholly new thing--"the church, which is his [Christ's] body," formed by the baptism with the Holy Spirit 1Cor 12:12,13 and in which the earthly distinction of Jew and Gentile disappears Eph 2:14,15 Col 3:10,11. The revelation of this mystery, which was foretold, but not explained by Christ Mt 16:18 was committed to Paul. In his writings alone we find the doctrine, position, walk, and destiny of the church.

Jamieson-Fausset-Brown Bible Commentary

6. Translate, "That the Gentiles are," &c. "and fellow members of the same body, and fellow partakers of the (so the oldest manuscripts read, not 'His') promise, in Christ Jesus (added in the oldest manuscripts), through the Gospel." It is "in Christ Jesus" that they are made "fellow heirs" in the inheritance of God: "of the same body" under the Head, Christ Jesus; and "fellow partakers of the promise" in the communion of THE Holy Spirit (Eph 1:13; Heb 6:4). The Trinity is thus alluded to, as often elsewhere in this Epistle (Eph 2:19, 20, 22).

Matthew Henry's Concise Commentary

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.