Ephesians 3:3-6 Amplified Bible (AMP)

3. [And] that the mystery (secret) was made known to me and I was allowed to comprehend it by direct revelation, as I already briefly wrote you.

4. When you read this you can understand my insight into the mystery of Christ.

5. [This mystery] was never disclosed to human beings in past generations as it has now been revealed to His holy apostles (consecrated messengers) and prophets by the [Holy] Spirit.

6. [It is this:] that the Gentiles are now to be fellow heirs [with the Jews], members of the same body and joint partakers [sharing] in the same divine promise in Christ through [their acceptance of] the glad tidings (the Gospel).

Ephesians 3