If you practice an excellent virtue without perceiving the taste of its aid, do not marvel; for until a man becomes humble, he will not receive a reward for his labor. Recompense is given, not for labor, but for humility.
Isaac of NinevehLet there always be a preponderance of mercy with you, even though you don't feel such mercy in yourself, as God has for the world ... A cruel and merciless heart is never purified. A merciful man is the doctor of his own soul, because as it were a by a strong wind from is heart he drives out the darkness of the passions.
Isaac of NinevehIf, at the time when the mind is praying it is distracted by any extraneous thought or worry about anything, then this prayer is not called pure.
Isaac of NinevehThe Lord bears all the weaknesses of men, but He does not bear a man who is always murmuring, and does not leave Him without chastisement.
Isaac of Nineveh