“…sometimes a man is unfair to himself, demanding more than he can give. He demands victory over his passions and grieves, worries, and resents himself when he sees that he is being taken over by those very passions that he had decided to leave behind. But is such indignation against oneself justified? No. Man will never be able to defeat his passions by his own power: They are overcome in us by the power of God. “
(St. Arsenia of Ust-Medvedits, ‘Spiritual Instructions’ in pravoslavie.ru)