Ulfilas (or Wulfila, perhaps meaning "little wolf") (around A.D. 310-383), bishop, missionary, and translator, was a Goth or half-Goth who had spent time inside the Byzantine Empire at a time when Arianism was dominant. Ulfilas was ordained a bishop by Eusebius of Nicomedia and returned to his people to work as a missionary. Ulfilas translated the Bible from Greek into the Gothic language. For this he established a Gothic alphabet writing system. Fragments have survived and are known as the Codex Argenteus, in the University Library of Uppsala.
Ulfilas converted many among the Visigoths and Ostrogoths, preaching an Arian Christianity, which when they reached the western Mediterranean, set them apart from their overwhelmingly Catholic neighbors and subjects.
The creed of Ulfilas, as appended to a letter praising him written by his foster-son and pupil the Scythian Auxentius of Durostorum (modern Silistra) on the Danube, who became bishop of Milan, is a clear statement of central Arian tenets, which separated God the father ("unbegotten") from the second, lesser God, the Christ ("only-begotten"), who was born before time and who created the world, and the Holy Spirit, created by thev Father through the Son:
- "I believe that there is only one God the Father, alone unbegotten and invisible, and in His only-begotten Son, our Lord and God, creator and maker of all things, not having any like unto Him. Therefore there is one God of all, who is also God of our God, And I believe in one Holy Spirit, an enlightening and sanctifying power. As Christ says after the resurrection to his Apostles: "Behold I send the promise of my Father upon you; but tarry ye in the city of Jerusalem until ye be clothed with power from on high." (Luke 24.49) And again: "And ye shall receive power coming upon you by the Holy Spirit." (Acts 1.8) Neither God nor Lord, but the faithful minister of Christ; not equal, but subject and obedient in all things to the Son. And I believe the Son to be subject and obedient in all things to God the Father."