The Practice of Piety presents the substance of several sermons Lewis Bayly preached while minister at Eversham. It was made into a devotional manual and soon became one of the most popular books in England. It was translated into Welsh, French, Hungarian, Polish, and several other languages.

The Practice of Piety is filled with scriptural and practical guidelines on the pursuit of holy living. Bayly begins his work with "a plain description of God in His essence, person, and attributes," understanding this to be the basis for piety; every grace that sinners need springs from the gracious character of God. He emphasizes the necessity of true faith and holy living, and explains how to attain and maintain readiness for Christ's second advent. Bayly then shows how to overcome obstacles to the pious life, stresses how piety is to be cultivated, and offers wise advice on the spiritual disciplines. He shows how to guide our thoughts, words, and actions in times of health as well as in times of sickness and affliction. He even provides directives to protect us from despair and the fear of death. In short, this is a book about how to live godly and die well.