Developments in biblical studies, neurosciences, and Christian philosophy of mind force theologians to reconsider the traditional concept of the immortal soul. At the same time, the concept itself tends to create axiological dualism between the body and the soul that in turn may lead to insufficient appreciation of the physical life in this world. A more holistic approach to the ontology of human beings is required. The aim of this study is to analyse the function of the concept of the soul in the dualistic anthropology of John Calvin and to compare it to the holistic anthropology of Karl Barth in order to answer the question of whether the transition from one to the other is possible without the loss of the functions fulfilled by the soul.