The struggle with a spirit of lust is a fierce struggle, longer than others, a daily struggle, and only a small number of people come to total victory. This struggle begins with the first ripe growth and does not finish until all the other passions have been mastered.
In this struggle, it is necessary to use two weapons. For the achievement of a perfect and pure chastity, bodily fasting is not enough (though it is of the utmost necessity). On top of that, compunction of soul and unremitting prayer against that most unclean spirit; then, constant study of the Scriptures together with prudent works, physical labour and hand-work. These things keep the heart from unchastity and bring it back to itself.
Above all, deep and true humility is needed, without which one will never attain victory over any passion. Victory over this passion is a freeing for the perfect purifying of the heart, from which, according to the words of the Lord, flow forth poison and grave ills: ‘For out of the heart proceed evil thoughts, … adulteries, fornications’ and so forth (Matt. 15:19).
- St. John Cassian (excerpt)