Introduction to the Devout Life, written by Saint Francis de Sales in 1609, is a classic of Catholic spirituality and a practical guide to achieving holiness in everyday life. Originally a series of spiritual guidance letters written by Francis de Sales to his cousin, Madame de Charmoisy, who lived in a court environment and wanted to remain devout amidst the hustle and bustle of the world. The book's core message is that holiness (devotion) is not just for monks or nuns, but can be achieved by anyone—artists, soldiers, servants, or housewives—without having to abandon their work responsibilities. Francis emphasizes that true devotion makes everyday life sweeter, more harmonious, and more orderly.