Martin Luther’s spiritual and theological development was deeply rooted in mystical traditions. During his early years as an Augustinian friar, he experienced mystical visions following the paths of Dionysian mysticism, while a few years later he was inspired by Ps-Bonaventure, Bernard of Clairvaux, and John Tauler. His early theology of penitence, as expressed in the Ninety-five Theses, derived from these sources, as did his description of justification in the image of bride and bridegroom in his tract On the Liberty of a Christian. Even more so, central elements in his theology were shaped by mystical influences, including his distinction between Law and Gospel, the doctrine of justification, and the concept of the priesthood of all believers. Thus, Luther’s theology should be seen as a reception and development deriving from the mystical discourse of the later Middle Ages.