Trouble dogged St. Alexander from the moment he became bishop of Alexandria in 312. Immediately, he had to deal with opposition from Meletius of Lycopolis, whose rigorism toward lapsed Catholics had led him into schism. He also had problems with Kolluth, a priest who had usurped the power to ordain deacons and priests.
Alexander’s biggest difficulty, however, was his controversy with the priest Arius. Arius viewed Alexander as a rival, and Alexander’s choice as bishop frustrated his ambition. In a greathearted gesture, Alexander put Arius in charge of an important parish. Then Arius began to preach errors that rocked the church for decades. He taught that Christ was not truly God, that the Son was a creature who at some time did not exist and was capable of sinning.
At first Alexander tried to use gentle persuasion to correct Arius. But when discussions with local clergy failed to convince him of his error, Alexander had a synod of Egyptian bishops condemn and excommunicate him. Afterwards, Arius flooded the East with propaganda in his defense. To counteract it, Alexander wrote numerous letters explaining his actions and exposing Arius’s error. The following passage comes from one of two such letters that have survived:
Oh, the new and ineffable mystery! The Judge was judged. He who absolves from sin was bound. He was mocked who once framed the world. He was stretched upon the cross who stretched out the heavens. He was given up to the tomb who raises the dead. The powers were astonished, the angels wondered, the elements trembled, the whole created universe was shaken, the sun fled away . . . because it could not bear to look upon the crucified Lord. . . .
. . . But when our Lord rose from death and trampled it down, when he bound the strong man and set man free, then every creature wondered at the Judge who for Adam’s sake was judged, . . . at the immortal dead, at the celestial buried in the earth. For our Lord was made man. He was condemned that he might impart compassion. He was bound that he might set free. . . . He suffered that he might heal our sufferings. He died to restore life to us. . . .
. . . For this cause he came down upon earth, that by pursuing death he might kill the rebel that slew men. For one underwent the judgment, and myriads were set free. One was buried, and myriads rose again. He is the mediator between God and man. He is the resurrection and salvation of all. He is the guide of the erring, the shepherd of men who have been set free, the life of the dead, the charioteer of the cherubim, . . . and the king of kings, to whom be the glory forever and ever. Amen.
After Emperor Constantine conquered the East in 324, he intervened in the controversy. He sent Hosius of Cordoba, his adviser, to attempt to reconcile Alexander and Arius. However, when Hosius understood the issues at stake, he joined forces with Alexander. Together they called a general council at Nicea in 325. Alexander and his colleague, St. Athanasius, led the orthodox party at the council, which condemned the Arian heresy.
Two years later Alexander died after naming Athanasius as his successor.