An Introduction to the Devout Life
Work written by Saint Francis de Sales, intended to lead "Philothea" (philos, loving; Theos, God), the soul living in the world, into the paths of devotion.
It consists of five books.
In the first the author helps the soul to free itself from all inclination to sin; in the second he teaches it how to be united to God by prayer and the sacraments; in the third he exercises it in the practise of virtue; in the fourth he strengthens it against temptation; and in the fifth he teaches it how to form resolutions and persevere.
It has been translated into nearly every language and has gone through innumerable editions.
New Catholic Dictionary