The article examines the history of writing and editorial preparation of the popular science book by E.G. Kagarov “Religions of the Ancient World”, accepted for publication in 1929 by the publishing house “Bezbozhnik”, but never published. The author identifies the reasons why the completed manuscript remained in the editorial portfolio and was not published. The Second Congress of the Union of Militant Atheists, held in the early summer of 1929, condemned the “opportunistic departure” from the class proletarian line in relation to religion, expressed in “culturalism” and “enlightenment” divorced from the tasks of the class struggle, so the publishing house “Bezbozhnik” refused to publish the book by E. G. Kagarov. His attempts to apply economic and sociological analysis to the history of religions and to determine the “production significance” of religious phenomena were recognized as insufficiently clearly expressed and lacking the necessary critical basis. © 2025, Amur State University. All rights reserved.