The course of lectures was prepared at the Faculty of Further Education of PSTGU, where hagiology has been taught since 2005 as part of the professional retraining program “Theology” and as a separate short-term advanced training course. Hagiology is a relatively new theological discipline that arose at the intersection of several theological sciences. The main subject of her study is spiritual perfection and holiness. Lectures are one of the possible options for an introductory training course in this discipline. The course comprehends the various paths to holiness and identifies the characteristic features of the feat of saints of each rank; an overview of the history of holiness in different countries of the Christian world is given, the spiritual continuity and mutual influence of the exploits of saints is shown; the principles of writing lives are revealed, approaches to the canonization of saints in Orthodoxy and Catholicism are explained. The conclusions of the course are based on the Holy Scripture, materials from the lives of saints, liturgical texts, patristic discussions about holiness. The lectures are intended for students of the Faculty of Further Education of PSTGU, as well as for everyone interested in hagiology. The lecture materials can serve as an additional source of information when studying the history of the Church and the history of the Russian Orthodox Church, and can be used in sermons and missionary work.