The article is devoted to the analysis of problematic aspects of the radicalization of religious dogmas, the causes and methods of their dissemination in online media, the study of the impact on the audience. A critical review of the scientific literature on this topic showed a surge in the interest of the online audience in the activities of non-traditional religious movements, revealing their radical characteristics. The global crisis and the situation of instability of the XXI century allowed many foreign religious emissaries to openly and actively engage in the propaganda of cults that pose a serious public threat. The authors draw attention to the lack of development of approaches to the analysis of extremist texts and the need to apply a phenomenological methodology to the study of religious extremism, stimulated in frequent cases by the mass media. The main attention is paid to media extremism as a scientific category. The research is based on the materials of sociopsychological examinations commissioned by the Center of Expertise of St. Petersburg State University. The methods of discourse analysis of media texts and forensic psycholinguistic examinations were used. The basic ones for the study were the sermons on network resources (YouTube videos) of the hieromartyr Sergius, the confessor of the Sredneuralsky Convent. The choice of the research object is explained by the fact that the author of the sermons (the "priest") caused enormous social, spiritual and even state damage by his behavior, actually subversive political activity and vicious nationalist ideology. The authors came to the conclusion: pseudo-religions broadcast in the mass media turn into a powerful tool of manipulation. But even within the framework of traditional Abrahamic religions, destructive formations can arise that act destructively in social, humanitarian and spiritual terms. Separate mass media act as a stimulator of this process.