The topic of this thesis is Jurgen Habermas' views on religion, especially in his two volumes The Theory of Communicative Action.  The introduction presents the sociological and the philosophical contexts in which Habermas' views may be understood. Part I is a reading of the main sections of The Theory of Communicative Action where different aspects of the human religious experience are considered by the German philosopher, and similar reading and comments of some extracts of a Conference held at Chicago in October 1988 on the contribution of Habermas' philosophy for theology. Part II proposes critiques and comments of Habermas' assumptions on religion and a renewed framework (lifeworld) into which the religious description finds a better place and role among the other human experiences.  The main hypotheses of this thesis are the following: (1) Habermas' thesis on communicative action is not influenced by his views on religion, (2) but his understanding of religion acts upon his theory of modernity.  Therefore, we will concentrate on the way Habermas' views on religion influence his thesis of modernity