In this, the first of a four-volume series, Father Studer offers a detailed study of how theology was done in the socio-cultural scene of the Christian community in the Constantinian and Theodosian eras (known as the age of 'The Church of the Empire' or 'The Imperial Church'). It defines the conditions in which pastors sought to help the faithful understand their religion and develops the thought through which the writers of the post-Nicene Church set out to actualize the Word of God as found in the sacred writings. Rather than narrowly focusing on major figures and their works, this historical investigation defines the context in which patristic theological inquiries were formed, since what is termed 'theology' today only gradually took shape in the early centuries of Christian living. Terminology, literary genres, the Bible, philosophy, heresy, art and architecture, theological currents, and sociopolitical circumstances in addition to people and events are some of the categories this volume explores to integrate in a holistic manner the developing theological methods of the Church.