The importance of Irenaeus’s work is that here we have a writing which may be considered the beginning of orthodoxy after the doctrinal chaos of the previous half-century. He gives us a lucid and detailed statement of the basic truths of faith, God, Christ and salvation. From the earlier period the fullest post-apostolic exposition of the Christian faith we possess is Justin Martyr’s writing, particularly his Dialogue with Trypho the Jew (c. AD 135). Obviously the dialogue with a Jew is more restricted,