John Cassian, Conferences I–X VIII.17: Of the fact that two angels always cling to every man

For Holy Scripture bears witness that two angels, a good and a bad one, cling to each one of us. And of the good ones the Saviour says: “Do not despise one of these little ones; for I say unto you that their angels in heaven do always behold the face of thy Father which is in heaven:” and this also: “the angel of the Lord shall encamp round about them that fear Him, and deliver them.” Moreover this also which is said in the Acts of the Apostles, of Peter, that “it is his angel.” But of both sorts the book of the Shepherd teaches us very fully. But if we consider about him who attacked the blessed Job we shall clearly learn that it was he who always plotted against him but never could entice him to sin, and that therefore he asked for power from the Lord, as he was worsted not by his (Job’s) virtue but by the Lord’s protection which ever shielded him. Of Judas also it is said: “And let the devil stand at his right hand.”