Theophilus of Antioch

Theophilus served as bishop of Antioch from approximately 169 to 183 CE, making him one of the most prominent Ante-Nicene Greek apologists. Born a pagan in the Tigris-Euphrates region of Mesopotamia, he converted to Christianity after studying the Hebrew Scriptures and went on to lead the church at Antioch with scholarly distinction. His only surviving work, the three-book Ad Autolycum, is a defense of Christian faith addressed to a pagan friend and holds the distinction of being the earliest known Christian text to use the Greek word trias (Trinity) for the Godhead, applying it to God, His Word (Logos), and His Wisdom (Sophia). He also reportedly wrote polemical works against Marcion and Hermogenes, as well as commentaries on the Gospels and Proverbs, all of which are now lost. Theophilus stands at the headwaters of Trinitarian theological vocabulary and represents the mature flowering of second-century Greek Christian apologetics.