In analyzing the role of gift and giving in Martin Luther’s theology, one almost inevitably has to deal with the contrast between Marcel Mauss’s description of archaic gift economy, where gifts and exchange are interconnected and gift exchange a total social fact, and Derrida’s critique of Mauss for talking of anything else but the gift, since only a gift uncontaminated by exchange deserves the proper name “gift.” Accordingly, any reading of Luther relating Luther’s theology to the reciprocity of giving seems, from the outset, to grasp anything but the cornerstone of his theology: the justification by faith alone apart from works of the law. Nevertheless, scholars in the early 21st century have been discussing Luther as a theologian of the gift. Some defend a position according to which Luther’s theology can only be rightly understood by maintaining that the divine gift is free and pure. Others argue that Luther’s mature theology allows for an integration of some kind of exchange as a vital part of the very doctrine of justification. In both cases, social anthropological gift studies can function as a lens for highlighting the heart of Luther’s theology, either negatively by presenting the absolute opposite of Luther’s understanding of divine giving in justification and creation or positively by revealing the very heart of the same. The young Luther vehemently criticized a piety regulated by economic principles and understood divine righteousness in contrast to human principles for righteousness. However, he soon began integrating reciprocal aspects from the traditional definition of righteousness into his doctrine of justification. This was possible due to an emphasis on the divine self-giving, revealed in Christ and slowly elaborated to cover Luther’s understanding of the whole Trinity. In this move, Luther seemed to have been influenced by Roman popular philosophy, which was widespread in the late renaissance, but biblical passages emphasizing reciprocal justice also played an important role. Advocators for understanding Luther’s theology from the perspective of inter-human gift exchange will argue that Luther’s theology of the gift is intimately related to his use of the figure of communicatio idiomatum, which allows the giver to share his attributes with the receiver.