Introduction. In the light of Marxist social ontology, the theoretical inconsistency of Marxist atheism is revealed.Methodology and sources. The contradictions between these two aspects of Marxism are examined in the context of the works of K. Marx, F. Engels, V.I. Lenin, R. Luxemburg, and a number of contemporary materialist philosophers. Marxist philosophy is analyzed in a postpositivist key as a set of research programs within which atheism should be seen as an optional, hypothetical element of their “protective belt”.Results and discussion. Marxist social ontology, which has a communist character, and Marxist atheism, which is based on the bourgeois Feuerbachian worldview, cannot coexist in the “solid core” of Marxist research programs. Materialist dialectics exposes the bourgeois-enlightenment idea of the omnipotence of human reason, on which Marx's conviction that “conscious planned control” of social production will abolish religion is based. Scientific atheism is just as impossible as scientific theism, because ideas about God do not lend themselves to an unambiguous scientific definition due to their apophatic aspect (which, among other things, does not allow for attributing authentic Christian theology to idealist philosophy). Socio-historical practice does not confirm the superiority of the atheistic worldview over the religious one. The rejection of permanent resistance to religion follows from the Marxist requirement of a concrete-historical approach to superstructural social phenomena. The general philosophical and anthropological basis of scientific analysis of different worldviews makes it possible to constructively engage in interfaith dialogue as well as dialogue between atheists and believers.Conclusion. In a world of transformed social forms, the concept of fact is radically problematized. And this calls into question the atheistic critique of religion along the lines of “illusion or reality”. As long as the question of authentic human reality is not resolved in practical terms, an objective critique of the various concrete-historical manifestations of religion and atheism is possible on the scale of research programs only through the parameter “humane or inhumane”, that is, through an analysis of the impact of this or that worldview on the development of living human individuals and the essential human forces.