Arius Arius (AD ca. 250 or 256 - 336) was a Berber Christian priest from Alexandria, Egypt in the early fourth century whose teachings, now called Arianism, were deemed heretical by the Church.In about the year 318, he was involved in a dispute with his bishop, Alexander of Alexandria, maintaining against him that Jesus, "the Son of God," was not consubstantial or coeternal with God the Father, but that there was once a time, before he was begotten, that he (Jesus) did not exist.