ANSWER: The men who went with the apostles to proclaim the gospel were not assistants in a formal sense. They too, were those involved in preaching the gospel according to the great commission of Mark 16:15-16. The task before them was great and, undoubtedly, the apostles alone could not have accomplished the feat of taking the gospel into all the world as was done by the time Paul wrote the book of Colossians (Colossians 1:6). That the Holy Spirit was also involved in such decisions can be seen in Acts13:2.