W. Austin Gardner
All were missionaries

The early church was a missionary church. Almost every book in the New Testament was written by a foreign missionary. Every epistle in the New Testament addressed to an individual was addressed to the convert of a foreign missionary. Every epistle addressed to a church was addressed to a foreign mission church. All of the apostles, except one, became a missionary; the one who didn’t become a missionary became a traitor. The disciples were first called “Christians” in a foreign land.
John Phillips, Exploring Colossians & Philemon: An Expository Commentary, The John Phillips Commentary Series (Kregel Publications; WORDsearch Corp., 2009), Col 1:6a.