'He must...be a model for everyone. He must be devoted entirely to the example of good living. He must be dead to the passions of the flesh and live a spiritual life. He must have no regard for worldly prosperity and never cower in the face of adversity. He must desire the internal life only. His intentions should not be thwarted by the frailty of the body, nor repelled by the abuse of the spirit. He should not lust for the possessions of others, but give freely of his own. He should be quick to forgive through compassion, but never so far removed from righteousness as to forgive indiscriminately. He must perform no evil acts but instead deplore the evil perpetrated by others as though it were his own. In his own heart, he must suffer the afflictions of others and likewise rejoice as the fortune of his neighbor, as though the good thing was happening to him. He must set such a positive example for others that he has nothing for which he should ever be ashamed. He should be such a student of how to live that he is able to water the arid hearts of his neighbors with the streams of doctrinal teaching. He should have already learned by practice and experience of prayer that he can obtain from the Lord whatever he requests, as though it were already said to him, specifically, by the voice of experience: "When you are speaking, I will say 'Here I am'"'
Gregory the Great, The Book of Pastoral Rule, p.43.