The Ladder of Divine Ascent," (Boston: Holy Transfiguration Monastery, 1978), Step26: On Discernment of Thoughts, Passions and Virtue

When our good and all-gracious Lord and Master sees people too lazy in their exercises, He lays their flesh low with sickness, an asceticism with less toil; and sometimes it also cleanses the soul from evil thoughts or passions. St. John Climacus