Over the course of twelve years (386-397), St. John Chrysostom gained popularity in Antioch because of the eloquence of his public speaking. What do we know about the beliefs and religious affiliation of the population of this city? This study focuses on the religious configuration of Antiochian people. It examines the public expression of the Christian attitude to the Pagans and Jews in the century of the victory of the Church. The author displays in his study a sensitive and judicious interest in the interaction of Christianity, Hellenism (Paganism) and Judaism in the second half of the 4th century in Antioch. He presents some of the relevant documents including Libanius's letters and speeches or Chrysostom's sermons. The results of the study indicate the extent to which the Church, so long after Constantine, still felt the ned to assert and defend its claims in the face of powerful challenges.