The book by a famous scientist, professor of history at Yale University (USA) describes the life and worldview of a Russian sect, whose members “made themselves eunuchs for the Kingdom of Heaven” (Matthew 19:12). Originating in the 18th century, the sect survived into the Soviet period, maintaining its faith and rituals despite persistent persecution. Engelstein's work introduces readers to the context of the most important contemporary discussions about group and individual identity, the formation of cultural boundaries and norms, and the sociocultural consequences of their violations