The study is devoted to understanding man and his existence as the self-revelation of God in the exegesis of Christianity from the period before the great councils to the Second Vatican Council. This volume of Textbooks of Catholic Theology (AMATESA), like the other books in the series, is intended to stimulate all who study this subject or are simply interested in basic theological positions and views in their desire to delve into the truths that are spoken of, in general, for everyone Christian Creed. This textbook is designed to turn the reader's gaze to God as the Triune Love, which serves as the basis of any theology. This book is intended to awaken the reader to highlight something important for himself within these “big” topics and, in accordance with this, turn to more detailed monographs and in-depth research.