Before reaching the age of 20, Athanasius wrote a treatise entitled On the Incarnation, affirming and explaining that Jesus was both God and Man. In about 319, when Athanasius was a deacon, a presbyter named Arius began teaching that there was a time before God the Father begat Jesus Christ when the latter did not exist. Athanasius responded that the Father's begetting of the Son, or uttering of the Word, was an eternal relationship between them, not an event that took place within time. Thus began catholic Christianity's fight against the heresy of Arianism. Athanasius fought consistently against Arianism all his life. He accompanied bishop Alexander to the First Council of Nicaea in 325, which council produced the Nicene Creed and anathematized Arius and his followers. On May 9, 328, he succeeded Alexander as bishop of Alexandria. As a result of rises and falls in Arianism's influence, he was banished from Alexandria only to be later restored on at least five separate occasions, perhaps as many as seven. This gave rise to the expression "Athanasius contra mundum" or "Athanasius against the world". During some of his exiles, he spent time with the Desert Fathers, monks and hermits who lived in remote areas of Egypt.