The article defines and substantiates the universal principles of catechization that are not bound to external conditions, but correspond to the main task of introducing people into the Church. This makes it possible to apply them to the catechumenal practice of any period in Church history. Although there is no single continuous catechumenal tradition and during the existence of active catechumenal practice in Church history (the II–V centuries) one can see a significant difference both in the form of catechism and in its content, the analysis of the whole set of ancient catechumenal practices shows that they have certain features in common. This suggests that the catechetical tradition of the Church is consistent with certain principles. There has always been the task of introducing people into the Church. On the one hand, the questions of instructing in faith recurred in the situation of missions to non-Christian peoples, especially in the case of adult baptism. On the other hand, the reference to early catechetical practices in the XX century stems from the solution of the vital needs of the time that arise from the ignorance of formally baptized people. Therefore it seems necessary to trace and analyze the basic principles of catechism, starting from the ancient Church, in order to define the boundaries of concepts and to be able to rely on these principles both in history and in modern times. As such universal principles of catechization, the paper highlights the Church, the unity of faith, prayer and life, as well as the staged approach to catechization.
Keywords: catechization, catechumenate, principles of catechization; churchliness; unity of faith, prayer and life; staged approach.