“Like the holy apostles, the holy fathers and the teachers of the Church confess the unity and uniqueness of the Orthodox Church with the divine wisdom of the cherubim and the zeal of the seraphim. Understandable, therefore, is the fiery zeal which animated the holy fathers of the Church in all cases of division and falling away and the stern attitude toward heresies and schisms. In that regard, the holy ecumenical and holy local councils are preeminently important. According to their spirit and attitude, wise in those things pertaining to Christ, the Church is not only one but also unique. Just as the Lord Christ cannot have several bodies, so He cannot have several Churches. According to her theanthropic nature, the Church is one and unique, just as Christ the God-man is one and unique.
Hence, a division, a splitting up of the Church is ontologically and essentially impossible.”
+ St. Justin Popovich, The Attributes of the Church
Originally published in Orthodox Life, vol. 31, no. 1 (Jan.-Feb., 1981), pp. 28-33
“Let us flee from those who reject patristic interpretations and attempt by themselves to deduce the complete opposite. While pretending to concern themselves with the literal sense of the passage, they reject its godly meaning. We should run away from them more than we would from a snake, for when a snake bites it kills the body temporarily, separating it from the immortal soul, but when these evil men get their teeth into a soul, they separate it from God, which is eternal death for that soul. Let us escape as far as we can from such people, and take refuge with those who teach piety and salvation in accordance with the traditions of the Fathers.”
+ St. Gregory of Palamas, Homily 34, On the Holy Transfiguration of Our Lord and God and Savior Jesus
“Shall we say: ‘Since it is lawful for an archbishop together with his associates to do as he pleases, let him be for the duration of his archbishopric a new Evangelist, another Apostle, a different Law-giver?’ Certainly not. For we have an injunction from the Apostle himself: If anyone preaches a doctrine, or urges you to do something against what you have received, against what is prescribed by the canons of the catholic and local synods held at various times, he is not to be received, or to be reckoned among the number of the faithful. And I forbear even to mention the terrible judgment with which the Apostle concludes (Gal. 1:8).”
“These people admit with the Latins that the Holy Spirit proceeds and derives His existence from the Son. Yet, with us, they say the Spirit proceeds from the Father. The Latins imagine that this addition to the Creed is lawful and just, but we will not so much as pronounce it. They state that unleavened bread is the body of Christ, but we dare not communicate it. Is this not sufficient to exhibit that they came to the Latin council not to investigate the truth, which they once possessed and then betrayed, but simply to earn some gold and attain a false union? Behold, they read two Creeds as they did before. They perform two different liturgies – one on leavened and the other on unleavened bread. They perform two baptisms – one by triple immersion and the other by aspersion; one with Holy Chrism and the other without it. All our Orthodox customs are different from those of the Latins, including our fasts, Church rites, icons, and many other things. What sort of union is this then, when it has no external sign? How could they come together, each retaining his own?”
“They (viz. the Latinizers) have dishonored and corrupted the
Church by making her mingle with those putrid members that have
been cut off from her for many years and are subject to countless
anathemas, and through communion with them they have besmirched the spotless Bride of Christ.”
+ St. Mark of Ephesus, Epistle to Hieromonk Theophanes
I am convinced that the further I depart from him [the Patriarch] and from those like him [the Latin-minded], the closer do I draw near God and all the faithful and the holy Fathers; and the more I am separated from them, by so much more am I united to the truth and the holy Fathers.
Hear, O you bishops; and hear, O you of the laity, how God speaks: I will judge between ram and ram, and between sheep and sheep. And He says to the shepherds: You shall be judged for your unskilfulness, and for destroying the sheep. That is, I will judge between one bishop and another, and between one lay person and another, and between one ruler and another (for these sheep and these rams are not irrational, but rational creatures): lest at any time a lay person should say, I am a sheep and not a shepherd, and I am not concerned for myself; let the shepherd look to that, for he alone will be required to give an account for me. For as that sheep that will not follow its good shepherd is exposed to the wolves, to its destruction; so that which follows a bad shepherd is also exposed to unavoidable death, since his shepherd will devour him. Wherefore care must be had to avoid destructive shepherds.
Even if the whole universe holds communion with the [Latinizing] Patriarch, I will not communicate with him. For I know from the writings of the holy Apostle Paul: the Holy Spirit declares that even the angels would be anathema if they should begin to preach another Gospel, introducing some new teaching.
Just as the fishermen hide the hook with bait and covertly hook the fish, similarly, the crafty allies of the heresies cover their evil teachings and corrupt understanding with pietism and hook the more simple, bringing them to spiritual death.
+ St. Isidore of Pelusium (Letter to Timothy the Reader, PG, 78:252)
Listen to me, people of all nations, men, women, and children, all of you who bear the Christian name: If any one preach to you something contrary to what the holy catholic Church has received from the holy apostles and fathers and councils, and has kept down to the present day, do not heed him. Do not receive the serpent’s counsel, as Eve did, to whom it was death. If an angel or an emperor teaches you anything contrary to what you have received, shut your ears.
+ St. John of Damascus, Apologia of St. John Damascene Against Those Who Decry Holy Images