Jamieson, Fausset & Brown

fellow helper concerning you--Greek, "fellow worker towards you." our brethren--the two mentioned in Co2 8:18, Co2 8:22. messengers--rather, as the Greek, "apostles": in the less strict sense (Act 14:14). of the churches--sent by the churches, as we are by the Lord (Phi 2:25). There was in the synagogue an ecclesiastical officer, called "the angel of the Church," whence the title seems derived (compare Rev 2:1).