Letter 233: Theodore Studite, Letter 233; Greek heading: Κωνσταντίνῳ κουράτορι.

A good report of your honor, coming into my ears, persuaded me to write to you, good sir. And what is this report? That, along with the rest of your virtue, which you have received from the grace of God, you still cling to guilelessness, guarding the orthodox faith like a treasure in the storehouse of your honored soul, and standing apart from communion with the heretics. I have had much gratitude toward my God in this, that laymen contend equally with monks to be well-pleasing to the Lord, fleeing the pit of heresy; for it is in truth a pit, brother, and a snare of the devil, and communion with them [the heretics] separates from Christ the one who is caught, and carries him far from the flock of the Lord. For as light is separated from darkness, so also is the orthodox partaking [of the Eucharist] separated from heretical communion; for the one enlightens, the other darkens; the one unites to Christ, the other to the devil; the one gives life to the soul, the other puts it to death. Well, then, do you act, running to the fountain of life and not drawing from the deadly cup of impiety, whose end is everlasting destruction. I call you most blessed; but see to it that, just as you began, you may also reach completion in the power of Christ, who is able to take you to himself, into his own kingdom and glory, through a good end. Pray for us sinners, brother sharing the same faith.