‘What is your only comfort in life and in death? That I am not my own, but belong body and soul, in life and in death to my faithful Saviour Jesus Christ.’ This first question and answer of the Heidelberg Catechism was among the best-known vernacula formulae among congregations across Reformed Europe. This beautifully-illustrated volume offers compelling detail about the context in which the Heidelberg Catechism was written and used. The book accompanied three exhibitions; two held in Heidelberg to mark the 450th anniversary of the first publication of the Catechism, and a third held in Apeldoorn to highlight the changing place of religion in the life of the House of Orange. This volume provides detailed descriptions of the rich material collected for these exhibitions. It also includes some seventeen articles about the Heidelberg Catechism and its use in the Palatinate and the Netherlands. Authors explain the complex religious politics of the ruling house of the Palatinate. The Heidelberg Catechism was written for Elector Frederick iii, composed mostly by the Silesian theologian Zacharias Ursinus, and first printed in German in 1563. The text betrayed influences of Wittenberg, Zurich and Geneva, and was stridently anti-Catholic in its denunciation of the mass. The Heidelberg Catechism was adopted as an instrument of instruction used in schools, churches and homes in the Palatinate. It was also quickly translated into a variety of languages and accepted as an authoritative statement of Reformed faith by Churches from Hungary to Scotland. Particularly close religious and political links developed between the Palatinate and the Netherlands. Dutch Reformed synods determined that the Heidelberg Catechism must be taught in sermons during Sunday afternoon services. Authors discuss why the Heidelberg Catechism proved to be so popular, how the Catechism functioned as a device for teaching ordinary people in the fundamentals of their faith, and how it became a means by which Reformed confessional identity was expressed on an international basis. It seems impossible to judge to what extent ordinary members of Reformed congregations understood the doctrine set out in the Catechism. However, most had at least learned key words and phrases off by heart, for example, that the bread and wine of Communion were ‘signs and pledges’ of Christ's sacrifice. This beautiful volume brings together the expertise of many scholars to illustrate and analyse the impact of the Heidelberg Catechism and to examine its place within early modern Reformed religion.