Passage
[to wit], that the Gentiles are fellow-heirs, and fellow-members of the body, and fellow-partakers of the promise in Christ Jesus through the gospel,
[to wit], that the Gentiles are fellow-heirs, and fellow-members of the body, and fellow-partakers of the promise in Christ Jesus through the gospel,
Ephesians 3:4 whereby, when ye read, ye can perceive my understanding in the mystery of Christ;
Ephesians 3:5 which in other generation was not made known unto the sons of men, as it hath now been revealed unto his holy apostles and prophets in the Spirit;
Ephesians 3:6 [to wit], that the Gentiles are fellow-heirs, and fellow-members of the body, and fellow-partakers of the promise in Christ Jesus through the gospel,
Ephesians 3:7 whereof I was made a minister, according to the gift of that grace of God which was given me according to the working of his power.
Ephesians 3:8 Unto me, who am less than the least of all saints, was this grace given, to preach unto the Gentiles the unsearchable riches of Christ;
The verse centers on "gentiles", "fellow-heirs", "fellow-members", "body", "fellow-partakers", "promise", "christ", and "jesus". It is saying that the verse draws attention to "gentiles" and "fellow-heirs", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 5's "which in other generation was not made..." into verse 7's "whereof I was made a minister according...", so "gentiles" and "fellow-heirs" belong inside that flow. In Ephesians context, the local focus is grace, union with Christ, the church, and new creation.
A plain takeaway is to answer the verse's own emphasis on "gentiles" and "fellow-heirs" with trust shaped by these words, not by a vague optimism outside the passage.