St. Maximus the Confessor

To harbor no envy, no anger, no resentment against an offender is still not to have charity for him. It is possible, without any charity, to avoid rendering evil for evil. But to render, spontaneously, good for evil -- such belongs to a perfect spiritual love. 1

Just as the intellect of a hungry man imagines bread and that of a thirsty man water, so the intellect of a glutton imagines a pro­fusion of foods, that of a sensualist the forms of women, that of a vain man worldly honor, that of an avaricious man financial gain, that of a rancorous man revenge on whoever has offended him, that of an envious man how to harm the object of his envy, and so on with all the other passions. For an intellect agitated by passions is beset by impassioned conceptual images whether the body is awake or asleep. . . When the desiring aspect of the soul is frequently excited, it implants in the soul a habit of self-indulgence which is difficult to break. When the soul's incensive power is constantly stimulated, it becomes in the end cowardly and unmanly. The first of these failings is cured by long exercise in fasting, vigils and prayer; the second by kindness, compassion, love and mercy. 2