Ephesians 3:6

That the Gentiles should be fellowheirs. — More exactly, are fellow-heirs, admitted already fully in God’s councils, as partially in actual fact to the kingdom of God.

And of the same body, and [fellow-] partakers of his promise. — These three words (of which the last two are peculiar to this Epistle) evidently describe progressive steps in the work of salvation. First comes the acceptance by God to a share in the inheritance, as “heirs of God, and joint-heirs with Christ” (Romans 8:17); next, incorporation into the mystical body of Christ; lastly, the actual enjoyment of a share in the promise — that is, all the spiritual blessings of the covenant, called “promises” because, though real in themselves, they are only an earnest of the hereafter. At every point stress is laid on their fellowship with Israel in all these gifts. The shoots of the wild olive (Romans 11:17) are first chosen out, then “grafted in,” and lastly “partake with the natural branches of the root and fatness of the olive tree.”

In Christ by the gospel. — These words should be joined with all the three preceding. Of all the privileges of the new life, the being “in Christ” is the substance, the reception of the gospel in faith the instrument.