Letter 512: Theodore Studite, Letter 512; Greek heading: Σεργίῳ ἡγουμένῳ.

Thanks be to the Lord, that Your Reverence is in good health; for this both your letter and the pair of brethren reported. We have also welcomed your intention and your desire to come to us, though you were prevented by the constraint of the civil wars and the molestation along the road. These evils the Lord our God will swiftly scatter, bringing the realm back to peace and indeed delivering it from the incursion of the Hagarenes [the Arabs/Muslims]; for we have been told also of the sword concerning them, of what sort and how great a thing it has been in those parts. And all these things are chastisements from God for our unrepentant wickedness. Nevertheless do you, good man and most honored brother, stand firm and play the man in leading the brotherhood, not sinking down into despondency even though the difficulties are many, not growing weary in the face of want even though your strength is being spent; but first of all - which is also the question of first account - guard the faith secure and unshaken, fleeing communion with the heterodox [those of false belief, here the iconoclasts] in every manner. For know that it is persecution, and not perfection, for you to sit at home and to remain unpersecuted, when the zealots for piety have suffered much and some have been crowned with the diadem of martyrdom. So that you have need of an exact life, one that fills up what was lacking in the submission to which your former superior submitted, and through him all of you by your acceptance of him; for as is the head, such also is the whole body. And I say these things not that you may be dissolved, but that you may keep yourselves with exactness and be strengthened by your non-participation in the heresy. Secondly, being sober be sober and being watchful be watchful, because many are they who war against us from on high, because many are the snares of the devil, because like a roaring lion he seeks whom he may devour; and one man he tries to gulp down by the pleasure of the flesh, another to tear away from the fellowship of the brethren by the disease of unbelief; and another he wounds through with the darts of envy, wishing to prove him a second Cain, while another he casts down by the fall of avarice, longing to make him known as a second Judas. And, in a word, his work night and day is our destruction. Look to it, guard by your conduct and your words the sheep of Christ, and your reward is great with God; for he himself said to the chief of the apostles: 'Simon son of Jonah, do you love me more than these? Feed my sheep.' So that the proof of love toward him is the shepherd's staff [exercised] according to right reason.