The article analyzes how several generations of Old Believers' ideologists perceived the concept of << Moscow, Third Rome >>. The author argued that at different stages of the history of the Old Believers various aspects of this concept got actualized. At the beginning the Old Believers prioritized the eschatological aspect, then the second generation of the movement's ideologists found the providential significance of Rus' as the universal center of Orthodoxy more promising for further discussions. The article examines the reflection of the << Third Rome >> doctrine and the complex of ideas associated with it in the literary tradition of the Vyg center of the Old Believers' movement (the first quarter of the 18th century). The study is based on the unpublished and yet -to -examined sermons of the leader of the Vyg community, writer, and polemicist Andrey Denisov. His works explored and developed the idea of the Rus' as the third and last Rome. However A. Denisov did not limit himself to the conclusion of the fall of the << Third Rome >> he came further and declared that for now only the Church of Old Believers represented by the Vyg Pustyn remained the last sanctuary of the true faith. A. Denisov created an important mythologem for the Old Believers' soteriology, claiming the passing on of godliness from the origins of Christianity through the Holy Rus' to the Old Believers. Since Vyg's literary school developed on the basis of modern rhetorical strategies, the article demonstrates how it combined ancient traditions of the religious literacy with cultural innovations during the period of transition from Medieval to Modern Times.