The research aims to prove the validity of studying the confessional language personality (LP) by domestic written monuments and to identify the representational aspects and means of the Old Believers’ worldview. The research material is original texts of two diaries (1915–1923 and 1956–1975) and personal notes (1940–1980) written by the Old Believers’ community members living in the north of Tomsk Oblast. The total lexical volume of these sources is about 15 thousand word usages. The analysis is based on the sociolinguistic portraiture method, which involves describing linguistic facts reflected in texts of different levels (graphics, vocabulary, grammar, etc.) and the authors’ personal qualities indicating their religious attitudes. We first examine LPs recognized a priori as confessional, then texts in search for information verifying the hypothesis of analysis in them. This analysis is based on Yuri Karaulov’s idea of the three-level LP structure, as well as the experience of describing individual religious LPs presented in linguistic works by Tolstova (2007), Chikovani (2016), Plotnikova (2021). We revealed all the features identifying this confessional community: marginality, insularity, heightened selfconsciousness, self-sufficiency, traditionalism, eschatology. These features are related to each other. All of them are manifested textually by different means: special lexical items, grammatical forms, graphics, descriptions of people of one’s circle and their activities in the coordinates of natural time and reclaimed areas, or by a hidden polemic suggesting the reflection of only positive aspects of being in this description. The markers of Old Believers’ LP at the verbal(grammatical)-semantic level are lexical items with a confessional meaning (Isus, Rozhestvo, bratets, otche), a wide variation due to bookish and written linguistic means (noshch’, ezero, glagolit’, desnitsa, sil’nAGO, vtorYY), mastery of the semi-uncial writing norms. The traditional values of the Old Believer world (LP’s cognitive level) manifested in records include the affirmation of the equality of all community members; family-like closeness of like-minded people; the recognition of authorities only in terms of spirituality (otche – godfather); the high significance of labor, books, sacred texts; the realized need for strict adherence to all religious canons (for example, the admissibility of only passive hunting, voluntary assumption of functions of community chroniclers). In our opinion, the tasks of preserving the Old Believers’ sacred space that express the writers’ interests and goals reflected in the records constitute the pragmatic (motivational) level of the confessional LP. Although we revealed the three-level structure mainly on the material of two specific confessional LPs, there are reasons to correlate the identified features with the generalized Old Believer’s LP.