The article combines short texts which were prepared for the dictionary of the sociology of religion, and from the author's point of view, focus on five critical concepts of the discipline. This series of concepts discussed in the paper begins with the term “religious conversion”, where the history of the concept, the specific social context, and the functions of relevant events and processes are considered. The second critical concept reviewed is that of the notion of “charisma”, with particular attention paid to the evolution of corresponding mythologems and the scenarios for their adaptation to specific contexts of sociology, political science, and business management. The third concept is the analysis of “sacred”, which is regarded as an integral definition of the objects of religious experience. Then, the notion of “civil religion” is discussed; the corresponding range of phenomena is viewed as a structure that mediates the relationships between society’s political culture and religion. The fifth concept analysed is the term “religious identity”, which is treated as designating invariant structures of individual’s everyday religious experience and derived from the identification both with transcendent “matters of faith” and with corresponding cult “community of the faithful”. In order to make the study of the materials easier, the concepts are arranged in order of the conversion of the “natural person”, as we are all born, and form a quite adequate introduction to the subject of the sociology of religion.