At the occasion of the 450th anniversary of the Heidelberg Catechism, an international conference on the spirituality of the Heidelberg Catechism was held at the Theological University Apeldoorn, 21-22 June 2013. This publication offers the plenary papers presented, and a selection of the short papers. While the papers center on the Catechism's spirituality, a wide range of topics is covered, from both historical and theological perspectives. These topics include: the roles of Ursinus and Olevianus, controverse theologians, anabaptist spirituality, comparisons with Calvin's Genevan Catechism and the later Synopsis of Purer Theology. Also, the distinct spirituality of faith, regeneration, the trinity, the law and prayer in the Heidelberg Catechism are scrutinized, besides the idea of mystical union and the art of dying and living. Three contributions reflect on the controversy on the Eucharist which has stamped the Heidelberg Catechism. From a practical-theological perspective, the preaching and teaching of the Catechism are discussed, as well as the mode of gospel presentation and the permanent character of catechetical instruction. So, this volume offers a broad range of scholarly perspectives on the Catechism. Its spirituality is famous for the first question and answer, on the only comfort in life and death: 'That I am not my own, but belong - body and soul, in life and in death - to my faithful Savior, Jesus Christ.'