Nicene and Post-Nicene Fathers, Ser. II, Vol. XIII:
Selected Epistles of Gregory the Great.: To Cyriacus, Patriarch of Constantinople.

Epistle XL.

To Cyriacus, Patriarch of Constantinople.

Gregory to Cyriacus, &c.

Observing diligently, most dear brother, how great is the virtue of peace from the Lord’s voice, which says, My peace I give unto you (Joh. xiv. 27), it becomes us so to abide in the love thereof as in no wise to give place to discord.  But, since we cannot otherwise live in its root except by retaining in mind and in deed the humility which the very author of peace has taught, we entreat you with befitting charity, that, treading down with the foot of your heart the profane elation which is always hostile to souls, you make haste to remove from the midst of the Church the offence of a perverse and proud title, lest you should possibly be found divided from the society of our peace.  But let there be in us one spirit, one mind, one charity, one bond in Christ, who has willed us to be his members.  For let your Holiness consider how hard it is, how indecent, how cruel, how alien from the aim of a priest, not to have that peace which you preach to others, and so abstain from offending your brethren out of pride.  But study this rather, how you may prostrate with the sword of humility the author of vain and profitless elation, to the end that in such a victory the grace of the Holy Spirit may claim you as a habitation for Himself, so that what is written may be plainly fulfilled in you; the temple of God is holy, which temple ye are (2 Cor. vi. 17.)

We commend to you in all things the bearer of these presents, our most beloved common son, the deacon Boniface, that in whatsoever may be needful he may find, as is becoming, the succour of your Holiness.