Introduction. The society of the 21st century is high-tech and digital, where people’s thoughts are polar and pluralistic. In such conditions, religion, although it has undergone secularization, remains the most important form of worldview. This article analyzes the methodological problems of eclecticization of religious traditions and adaptation of religious beliefs in a post-secular society. Theoretical analysis. Three main problems have been identified. First, the obscurity of religious beliefs as a form of social knowledge. Second, the gap between canonical knowledge and subjective religious belief as a reason for the eclecticization of religious traditions, as a result of which a special form of social knowledge arises. Can such social knowledge be called religious if eclecticization undermines the traditional and orthodox nature of the sacredness and inviolability of religious knowledge? Third, the place and role of tradition in keeping religious beliefs consistent with religious knowledge. Conclusion. Eclecticization of religious traditions can lead to the misunderstanding of finite meanings, which can be followed by destructive behavior (for example, extremist tendencies). To prevent clash of interests, it is necessary to have joint control by the state, religious institutions, and social movements to ensure social stability.