Abstract
The article is devoted to one of the forms of interaction between believers of Kazakhstan and the authorities, namely, letters from citizens to the state authorities. These letters of complaint against the actions of local officials led to the emergence of a set of documents that were deposited in archival fund. They became the main documentary base of the research. The concept of cultural adaptation of ethnic groups was used as a methodology to characterise the mechanisms of adaptation of believers to the requirements of the anti-religious policy of the Soviet state. The systemic analysis of the documents showed the informational potential of believers' letters as a narrative base that allows reconstruction the history of relations between the Soviet state and religious organisations. The letters of believers’ form ideas about religious discourse and the spiritual state of society. They reflect the religious feelings of Soviet people and characterise the level of religiosity of society. They express the reaction of ordinary citizens to the confessional policy of the state and the methods of its implementation. The informative content of letters, as sources for research into the methods of religious legislation, is often more comprehensive than the content of official documents and reports.