Ephesians 6:19–20

Paul's mission was to help non-Jews (Gentiles) understand they are now accepted by God and welcomed into God's church.

the mystery of the gospel: See study notes on 1:8–10; 3:3.

I am an ambassador in chains: Although writing as a prisoner (see 3:1; 4:1), Paul knew his role as God's ambassador was to continue speaking boldly for God (compare 2 Corinthians 5:20) .