6 Since then our Lord and Saviour Jesus Christ has instructed us by His own mouth, and also has signified to us by the Apostle concerning such men, we accordingly being personal witnesses of their impiety, have anathematized, as we said, all such, and declared them to be alien from the Catholic Faith and Church. And we have made this known to your piety, dearly beloved and most honoured fellow-ministers, in order that should any of them have the boldness to come unto you, you may not receive them, nor comply with the desire of Eusebius, or any other person writing in their behalf. For it becomes us who are Christians to turn away from all who speak or think any thing against Christ, as being enemies of God, and destroyers of souls; and not even to “bid such God speed,” lest we become partakers of their sins, as the blessed John has charged us. Salute the brethren that are with you. They that are with me salute you.
Presbyters of Alexandria.
Source: Deposition of Arius (New Advent)