ISB ~ 2 Corinthians 8 v18

the brother who is famous:Unidentified, but apparently well-known.

preaching of the gospel:The Greek is simply “in the gospel”. Some ancient writers identified this “famous” brother with the evangelist Luke and the “gospel” in question with the Gospel of Luke. This is uncertain, and to an extent improbable, since in Paul’s letters the word “gospel” refers to the message of salvation, not to a written narration of Jesus’ life and ministry. It is true, in any case, that Luke was one of Paul’s missionary associates (2 Tim 4:11; Philem 24).