The article examines how Orthodox non-governmental organizations (ONGOs) founded by lay believers function as mediators of postsecular dialogue between the religious subsystem and secular subsystems (political, economic, and artistic) in contemporary Russian society. Its central research question is how ONGOs grounded in Orthodox values construct dialogue with these subsystems and how religious norms and representations are translated into the language of civic engagement and public practices. The study’s methodological framework combines Jürgen Habermas’s postsecular epistemology with J. Berger’s concept of the “organizational substratum”, which focuses on the value-laden and meaning-generating foundations of organizational behaviour. The empirical base draws on case studies of four ONGOs (“Union of Orthodox Entrepreneurs”, “Guild of Russian Entrepreneurs”, the movement “Eternally Alive”, and the centre “Leningrad Volunteer”), sixteen semi-structured interviews with their founders and activists, and qualitative content analysis of Russian Orthodox Church doctrinal documents and media materials. The findings show that lay-initiated ONGOs generate a specific “organizational substratum” grounded in doctrinal interpretations of labour, property, gift, patriotism, and family, while operationalizing these in the form of entrepreneurship, small-business cooperation, volunteering, and museum-based and patriotic initiatives. These organizations translate religious values into the idioms of secular subsystems: Orthodox-inspired entrepreneurship into economic discourse, the religious code “Orthodox people” into the political code “Russian people”, and doctrinal patriotism and family values into practices of preserving historical memory, fostering civic participation, and building local solidarity. The article argues that such ONGOs act as postsecular mediators that generate hybrid forms of civic activity which cannot be reduced to the binary opposition “religious vs. secular” and therefore require analysis within a shared comparative field alongside other actors of civil society.