Theologia Germanica: Christianity between the Middle Ages and Luther’s reformation English summary The main subject of this master project is a devotional text about the path to reconciliation, salvation, and ‘illumination’ from around 1350, found by Martin Luther in a monastery library near Frankfurt and published by him in 1518 – the year before publicly inaugurating his reformatory work. In his Foreword to the text, which is written by an anonymous Christian contemplative master, Luther enthusiastically recommended the book with these words: “Next to the Bible and Saint Augustine no other book has come to my attention from which I have learned – and have desired to learn - more concerning God, Christ, man, and what all things are”. To emphasise the importance of the book as foundational for his own, German, theology, he gave it the title, Theologia Germanica. After a short introductory account of the societal, cultural and ecclesiastical conditions of the 14’th century, which saw a widespread up-welling of devotional Christian spirituality all over the European continent - the movement of “The Friends of God” in particular of which Theologia Germanica is a mouthpiece - a thorough outline will be given of its essential christological and ontological reflections concerning the relation between God, Jesus Christ and man, as well as epistemological considerations on the relation between the ‘heavenly eternal’ and the ‘earthly temporal’, and on how we can – or cannot possibly - know anything about God. And, last but not least, of its anthropological considerations as to why God ‘incarnated’ in the human person of Jesus and what His mission was – all to make it clear and understandable for the reader what it implies, presupposes and requires for someone to follow Christ and thus to be a Christian. The reflections and New Testament-near renderings of the essential subject matter of Christendom, according to Theologia Germanica, are surprising – not only because of the simplicity, clarity, and scope of presentation – but also for what is left out. Thus, in this humble treaties on what Christianity entails, which is at the same time the testimony of a spiritual master on the mystical path to salvation and ‘illumination’, there is no mention at all of the doctrines, essential to the theology of Luther’s, namely: the doctrines of original/heretical sin, the ‘double predetermination’, or the doctrines of atonement, i.e. of how Jesus suffered the death on the cross as a sacrificial offer, as ‘Stellvertreter‘, who caried our sins and conquered death for our sake and salvation. It is the intention of this master project to investigate how these interrelated doctrines originated and how they fare with the Word of the New Testament’s Gospels on the teaching, life, and works of Jesus Christ. Furthermore, to investigate what caused Luther to distance himself from what he once praised as the foundations of his theology - and, lastly, to attempt an answer to the question as to whether Luther’s theology is a creative extension and reformed continuation of a late medieval Christian mysticism, as recently suggested by leading Luther scholars.