Relations between the Russian Orthodox Church of the Moscow Patriarchate and the Russian Orthodox Old Believers’ Church through the Prism of Traditional Religious Terminology

The issue of relations between the Russian Orthodox Church of the Moscow Patriarchate (ROC MP) and the Russian Orthodox Old Believers’ Church (ROOBC) constitutes a complex theological and religious studies problem. Today, these eccle-siastical institutions share a fundamental dogmatic unity: they profess belief in the core doctrines expressed in the Niceno–Constantinopolitan Creed, recognize the Seven Ecumenical Councils, and uphold a common understanding of the sacraments. How-ever, this doctrinal agreement coexists with a profound canonical schism whose roots lie in the reforms of Patriarch Nikon in the seventeenth century. The current situation demonstrates the limitations of the traditional religious studies categories of confession and denomination for characterizing the relationship be-tween the ROC MP and the ROOBC. On the one hand, they cannot be unequivocally described as different confessions, given their shared dogmatic core, which funda-mentally distinguishes their relationship from, for example, the differences between Orthodoxy and Protestantism. On the other hand, the term denomination, which implies coexistence within a single confession accompanied by mutual recognition, is also inapplicable, since the schism is fundamental in nature and affects both the understanding of the essence and role of ritual and the conception of the boundaries and nature of the Church. Thus, the ROC MP and the ROOBC represent a unique case of two churches divided not by dogmatic differences but by historical-canonical and ritual factors. This circumstance necessitates the de-velopment of more nuanced analytical tools for their description that go beyond the classical confessiological paradigm.