The debate regarding the applicability of the secularization thesis needs to make a sharp distinction between the context in which it was created and the grounds for its validity. The aim of this essay is to find empirically and theoretically wellfounded arguments against the secularization theory and to examine whether they are justified or not. But before announcing one’s intention of criticizing the secularization theory, one needs to know what it actually says. Frequently an abridged, unilateral concept of the theory is used enabling one to dissociate oneself from it critically. Therefore, this essay starts with a brief presentation of the main presumptions of the secularization theory, goes on to list the major points of criticism before ending with a discussion of their justification.