At this synod, held in the year 325, Athanasius, a young deacon in the Alexandrian church, came for the first time into notice as the champion of Alexander against Arius, who was then placed upon his trial.  All the authority, eloquence, and charity of the emperor were needed to quell the tumultuous passions of the assembly.  It ended its stormy labours by voting what was called the Homoousian doctrine, that Jesus was of one substance with God.  They put forth to the world the celebrated creed, named, from the city in which they met, the Nicene creed, and they excommunicated Arius and his followers, who were then all banished by the emperor.  The meeting had afterwards less difficulty in coming to an agreement about the true time of Easter, and in excommunicating the Jews; and all except the Egyptians returned home with a wish that the quarrel should be forgotten and forgiven.

This first attempt among the Christians at settling the true faith by putting fetters on the mind, by drawing up a creed and punishing those that disbelieved it, was but the beginning of theological difficulties.  These in Egypt arose as much from the difference of blood and language of the races that inhabited the country as from their religious belief; and Constantine must soon have seen that if as a theologian he had decided right, yet as a statesman he had been helping the Egyptians against the friends of his own Greek government in Alexandria.

After a reasonable delay, Arius addressed to the emperor a letter either of explanation or apology, asserting his full belief in Christianity, explaining his faith by using the words of the Apostles’ Creed, and begging to be re-admitted into the Church.  The emperor, either from a readiness to forgive, or from a change of policy, or from an ignorance of the theological controversy, was satisfied with the apology, and thereupon wrote a mild conciliatory letter to Athanasius, who had in the meantime been made Bishop of Alexandria, expressing his wish that forgiveness should at all times be offered to the repentant, and ordering him to re-admit Arius to his rank in the Church.  But the young Athanasius, who had gained his favour with the Egyptian clergy, and had been raised to his high seat by his zeal shown against Arius, refused to obey the commands of the emperor, alleging that it was unlawful to re-admit into the Church anybody who had once been excommunicated.  Constantine could hardly be expected to listen to this excuse, or to overlook this direct refusal to obey his orders.  The rebellious Athanasius was ordered into the emperor’s presence at Constantinople, and soon afterwards, in 335, called before a council of bishops at Tyre, where he was deposed and banished.  At the same council, in the thirtieth year of this reign, Arius was re-admitted into communion with the Church, and after a few months he was allowed to return to Alexandria, to the indignation of the popular party in that city, while Athanasius remained in banishment during the rest of the reign, as a punishment for his disobedience.