The present study asks how to speak of God in post-metaphysic times. In the first part, with reference to existential philosophy, I will show that even in postmodernity the question of God ? and thus the question of the meaning of live ? has not become obsolete and that the postmodern human being still perceives a »metaphysical deficit«. In this context, Bernhard Braun?s philosophy of culture will have particular relevance. In a further step I will attempt, based on the analysis of the films by Ingmar Bergman, to show the lack of acceptance of Christian faith in the post-war period. Attention is given to questions of European cultural history, showing that Bergman's considerations are of lasting relevance. The main part of this study deals with the fundamental theological approach of the philosopher of religion Eugen Biser (born 1918), and asks how his theory of theology may be seen as a suitable response to the cited »metaphysical deficit« and Bergman?s critique of Christianity. At the same time, this part also provides systematic representation of Eugen Biser?s so-called "New Theology", which has not been comprehensively discussed from the perspective of the philosophy of religion up to now. The concluding considerations in the fourth part could be taken as an invitation to continue the reflections begun in this work on the background of the perception of the »metaphysical deficit« as an existential challenge in postmodernity.