The religious life of Orthodox believers under the conditions of persecution in the 20th century, especially from the mid-20s to the first half of the 40s, has not been sufficiently studied. Many communities, including brotherhoods, were forced to go underground due to the repressive policies of civil authorities. This is associated with a number of problems in providing this topic with archival sources. The article examines the life of the Orthodox brotherhood founded in 1924 by Bishop Makarii (Opotskii), which existed in several cities in northwestern Russia until 1942. The source base was not only materials from state and departmental but also private archives, as well as the results of field research. The article is based on the principles of historicism, comprehensiveness and scientific objectivity; methods of the micro-historical direction are used: historical-genetic, comparative; oral history method – interviews. The study showed that the brotherhood was able to survive all the waves of persecution of the 1920s and 1930s. In the 1920s, it showed noticeable resistance to Cherepovets renovationism and carried out legal activities within the framework of what was permitted by the civil authorities. The main activity was education. In 1937 it became illegal. The principles thanks to which the brotherhood managed to maintain its functionality were identified: concern for the presence of leaders, maximum maintenance of communication regardless of location, mutual trust between members of the community. Thanks to this, the brotherhood was able to practice such forms of religious life as common worship, regular participation in the sacraments, reading of the Holy Scriptures, sermons and spiritual conversations. It seems promising to compare the brotherhood of Bishop Makarii (Opotskii) with one or more similar communities operating in the same period or on the same territory