"Three Treatises" is a collection of seminal works by a prominent religious reformer, focusing on the need for religious reformation and critiquing the Roman Catholic Church's practices. The first treatise discusses the Christian's spiritual nobility and priesthood, arguing that faith alone, not church rituals or hierarchy, connects one to God. The second treatise criticizes the Roman Church's wealth, advocating for the abolition of private mass and the selling of indulgences. The third treatise, written as an open letter to the Christian nobility, calls for the reform of the Church by secular authorities.

This book is a comprehensive introduction to Christian theology and doctrine, written during the Protestant Reformation. The text outlines the author's views on subjects such as the nature of God, the authority of scripture, original sin, and salvation through Christ. The book also provides a detailed examination of the Ten Commandments and the Apostles' Creed, while offering a critique of the Catholic Church and its practices. The author's interpretation of Christianity, as presented in this work, has had a significant influence on the development of Protestant theology, particularly within Reformed churches.