Ephesians 3:4

by which, when you read, you may understand my knowledge in the mystery of Christ),

Surrounding context

3:3 how that by revelation He made known to me the mystery (as I have briefly written already,

3:4 by which, when you read, you may understand my knowledge in the mystery of Christ),

3:5 which in other ages was not made known to the sons of men, as it has now been revealed by the Spirit to His holy apostles and prophets:

Translation and sources