<P> The book was written as an introductory textbook on the Protestant faith for those with some previous knowledge of theology and covered a broad range of theological topics from the doctrines of church and sacraments to justification by faith alone and Christian liberty . It vigorously attacked the teachings of those Calvin considered unorthodox, particularly Roman Catholicism, to which Calvin says he had been "strongly devoted" before his conversion to Protestantism . </P> <P> The Institutes is a highly regarded secondary reference for the system of doctrine adopted by the Reformed churches, usually called Calvinism . </P> <P> John Calvin was a student of law and then classics at the University of Paris . Around 1533 he became involved in religious controversies and converted to Protestantism, a new Christian reform movement which was persecuted by the Catholic Church in France, forcing him to go into hiding . He moved to Basel, Switzerland, for safety in 1535, and around this time he must have begun writing a summary of theology which would become the Institutes . His Catholic opponents sought to associate him and his associates (known as Huguenots in France) with radical Anabaptists, some of whom had been defeated after a long siege in the Münster Rebellion in June 1535 . He decided to adapt the work he had been writing to the purpose of defending Protestants suffering from persecution from false accusations that they were espousing radical and heretical doctrines . The work, written in Latin, was published in Basel in March 1536 with a preface addressed to King Francis I of France, entreating him to give the Protestants a hearing rather than continue to persecute them . It is six chapters long, covering the basics of Christian faith using the familiar catechetical structure of the Ten Commandments, the Apostles' Creed, the Lord's Prayer, and the sacraments, as well as a chapter on Christian liberty and political theology . Soon after publishing it, Calvin began his ministry in Geneva, Switzerland . </P> <P> The Institutes proved instantly popular, with many asking for a revised edition . In 1539, Calvin published a much larger work, with seventeen chapters of about the same length as the six chapters of the first edition . It includes many references to classical authors and Church fathers, as well as many additional references to the Bible . Calvin's epistle to the reader indicates that the new work is intended for theological students preparing for ministry . Four chapters were added in a third edition in 1543, and a 1550 edition was published with only minor changes . The fifth and final edition with which Calvin was involved, and which is used by scholars as the authoritative text, is 80% larger than the previous edition and was published in Geneva in 1559 . </P>

Who had a large influence and ministry in switzerland and wrote institutes of the christian religion