If we detect any trace of hatred

in our hearts against any man whatsoever for committing any fault, we are utterly estranged from love for God, since love for God absolutely precludes us from hating any man.

Maximos the Confessor in the Philokalia volume ii, p. 54

Christians above all men

are forbidden to correct the stumblings of sinners by force. When secular judges convict wrong-doers under the law, they show that their authority is complete, and compel men, whether they will or no, to submit to their methods. ...God gives the crown to those who are kept from evil, not by force, but by choice.

St. John Chrysostom, Six Books on the Priesthood, p. 56

The Way of Life is this:

Thou shalt love first the Lord thy Creator, and secondly thy neighbor as thyself; and thou shalt do nothing to any man that thou wouldst not wish to be done to thyself.

What you may learn from these words is to bless them that curse you, to pray for your enemies, and to fast for your persecutors. For where is the merit in loving only those who return your love? Even the heathens do as much as that. But if you love those who hate you, you will have nobody to be your enemy.

from Early Christian Writings; The Didache, p. 191

A brother asked

one of the elders: What is humility? The elder answered him: To do good to those who do evil to you. The brother asked: Supposing a man cannot go that far, what should he do? The elder replied: Let him get away from them and keep his mouth shut.

From The Wisdom of the Desert pp. 53-54

The inclination to irritability

is given to us to use against [our own] sin, and we were never meant to use it against our fellow men. When we do, we act contrary to nature. We use irritability in this wrong, deflected way because we are proud. You must, of course, strive to curb your irritability; but guard yourself against being elated if you succeed.

from Russian Letters of Spiritual Direction 1834-1860 Macarius, Starets of Optino, p. 79