The collection includes articles by three prominent Russian theologians - Metropolitan Anthony (Khrapovitsky 1936), the Hieromartyr Hilarion (Troitsky 1929) and the schiarchimandrite Sophrony (Sakharov 1993). The articles are written at different times, but are nevertheless organically related to each other in their content. Yet together they both in theological and moral terms go back to the words of the high priestly prayer of Christ for all those who believe in Him: “... let them be one, just as we are” (Jn. 17, 11) — let Christians be one with each other in the image of the unity of the Most Holy Trinity, in imitation of the Divine nature . This is the central idea of the Church, which inextricably connects the Christian doctrine of man with the Christian doctrine of God the Trinity and has a direct practical (soteriological) significance - it reveals the image of the ecclesial likening of man to God.