‘Jesus [or Joshua as the name also means], which is called Justus, who are of the circumcision’ – that is to say, he and Mark and probably also Aristarchus are Jews. ‘These only are my fellowworkers unto the kingdom of God, which have been a comfort unto me.
That is a challenge to us. When you were first saved, you witnessed a great deal. Are you still? Every opportunity praying for them, reaching out to lost people, helping among the children in Sunday School, in visitation and so on? Would Paul be able to say of you, ‘This person is a great encouragement to me because he works for the kingdom. She is also among her contacts an evangelist and a witness’?