Floregium Chalcedonian formula
Here are quotes that support Chalcedon and teach our position
But the truth is, we find that He is expressly set forth as both God and Man; the very psalm which we have quoted intimating (of the flesh), that “God became Man in the midst of it, He therefore established it by the will of the Father,”—certainly in all respects as the Son of God and the Son of Man, being God and Man, differing no doubt according to each substance in its own especial property, inasmuch as the Word is nothing else but God, and the flesh nothing else but Man. Thus does the apostle also teach respecting His two substances, saying, “who was made of the seed of David;” in which words He will be Man and Son of Man. “Who was declared to be the Son of God, according to the Spirit;” in which words He will be God, and the Word—the Son of God. We see plainly the twofold state, which is not confounded, but conjoined in One Person—Jesus, God and Man. Concerning Christ, indeed, I defer what I have to say. (I remark here), that the property of each nature is so wholly preserved, that the Spirit on the one hand did all things in Jesus suitable to Itself, such as miracles, and mighty deeds, and wonders; and the Flesh, on the other hand, exhibited the affections which belong to it…Forasmuch, however, as the two substances acted distinctly, each in its own character, there necessarily accrued to them severally their own operations, and their own issues. Learn then, together with Nicodemus, that “that which is born in the flesh is flesh, and that which is born of the Spirit is Spirit.” Neither the flesh becomes Spirit, nor the Spirit flesh. In one Person they no doubt are well able to be co-existent. Of them Jesus consists—Man, of the flesh; of the Spirit, God—and the angel designated Him as “the Son of God,” in respect of that nature, in which He was Spirit, reserving for the flesh the appellation “Son of Man.” In like manner, again, the apostle calls Him “the Mediator between God and Men,” and so affirmed His participation of both substances.
Tertulian of Carthage, Against Praxeas, Ch 27
With this substance of the soul mediating between God and the flesh (for it was not possible for the nature of God to be mingled with a body without a mediator) there is born, as we said, the God-man,” the medium being that substance for which it was certainly not contrary to nature to assume a body.”... And, moreover, the Son of God is said to have died, that is, in virtue of that nature which could accept death; and he, who is proclaimed as coming in the glory of God the Father with the holy angels, is called the Son of Man.** And for this reason, throughout the whole of Scripture, the divine nature is spoken of in human terms as much as human nature is adorned with marks indicative of the divine. For of this, more than anything else, can that which is written be said, that They shall both be in one flesh, and they are no longer two, but one flesh.” For the Word of God is thought to be more in one flesh with the soul than a man with his wife. And, moreover, to whom is it more fitting to be one spirit with God than to this soul, which has so joined itself to God through love that it may deservedly be said to be one spirit with him?
Origen of Alexandria, On First Principles, John Behr p207-209
“We curse those who ascribe the sufferings to the Godhead, and those who call Christ a crucified man and do not confess that he was crucified in his whole divine hypostasis.”
Felix of Rome, Frag. 186 (Lietzmann p. 319),
Do you see that thus are proclaimed His humanity and His divinity, that death is attributed to the man, and the quickening of the flesh to the God, though He Who dies and He Who raises the dead to life are not two, but one Person? The flesh stripped off is the dead Christ: He Who raises Christ from the dead is the same Christ Who stripped from Himself the flesh. See His divine nature in the power to raise again, and recognize in His death the dispensation of His manhood. And though either function is performed by its proper nature, yet remember that He Who died, and raised to life, was one, Christ Jesus
Saint Hilary of Poitiers, On the Holy Trinity, 9, 11
There is not one Son of Man and another Son of God; nor one in the form of God, and another born perfect man in the form of a servant: so that, as by the nature determined for us by God, the Author of our being, man is born with body and soul, so likewise Jesus Christ, by His own power, is God and Man with flesh and soul, possessing in Himself whole and perfect manhood, and whole and perfect Godhead
Saint Hilary of Poitiers, On the Holy Trinity, Book 10, 19
A truce, then, to vain wranglings over words, for the Kingdom of God, as it is written, consisteth not in persuasive words, but in power plainly shown forth. Let us take heed to the Distinction of the Godhead from the Flesh. In Each there speaks One and the Same Son of God, for Each Nature is Present in Him; yet while it is the Same Person Who speaks, He speaks not always in the Same Manner. Behold in Him, now the Glory of God, now the affections of Man. As God He speaks the things of God, because He is the Word; as Man He speaks the things of Man, because He speaks in my Nature.
Saint Ambrose of Milan, Exposition on the Christian Faith, Book II, Ch. 9, sec. 77
This is the wish of our schoolmaster Galatians 3:24 the law, of the prophets who intervened between Christ and the law, of Christ who is the fulfiller and end Hebrews 12:2 of the spiritual law; of the emptied Godhead, Philippians 2:7 of the assumed flesh, Hebrews 2:14 of the novel union between God and man, one consisting of two, and both in one.
Saint Gregory of Nazianzus, Oration 2, 23
He came forth then as God with that which He had assumed, One Person in two Natures, Flesh and Spirit, of which the latter deified the former. O new commingling; O strange conjunction; the Self-Existent comes into being, the Uncreate is created, That which cannot be contained is contained, by the intervention of an intellectual soul, mediating between the Deity and the corporeality of the flesh. And He Who gives riches becomes poor, for He assumes the poverty of my flesh, that I may assume the richness of His Godhead. He that is full empties Himself, for He empties Himself of His glory for a short while, that I may have a share in His Fulness.
Saint Gregory of Nazianzen, Orations 38
And (if I am to speak concisely) the Saviour is made of elements which are distinct from one another (for the invisible is not the same with the visible, nor the timeless with that which is subject to time), yet He is not two Persons. God forbid! For both natures are one by the combination, the Deity being made Man, and the Manhood deified or however one should express it. And I say different Elements, because it is the reverse of what is the case in the Trinity; for There we acknowledge different Persons so as not to confound the persons; but not different Elements, for the Three are One and the same in Godhead.
Saint Gregory of Nazianzus, Letter 101 To Cledonius the Priest
He orders two small, living, clean birds to be taken, so that you might understand from winged creatures the man from heaven, at once man and God, in two natures, inasmuch as he came to be in the separate definition that belongs to each. He who shone forth from God the Father was "Word, in flesh from a woman.”
Saint Cyril of Alexandria, Patrologia Graeca Vol. 69, 576B
Your Perfection expounds the rationale of the salvific Passion most correctly and very learnedly when you assert that the Only Begotten Son of God, in so far as he is understood to be, and actually is, God, did not himself suffer [bodily things] in his own nature, but suffered rather in his earthly nature.
Saint Cyril of Alexandria, Second Letter to Succensus
Now, He says, is my soul troubled; and what shall I say? Father, save one from this hour: but for this cause came I unto this hour. See I pray you in these words again how the human nature was easily affected by trouble and easily brought over to fear, whereas on the other hand the Divine and ineffable Power is in all respects inflexible and dauntless and intent on the courage which alone is befitting to It. For the mention of death which had been introduced into the discourse begins to alarm Jesus, but the Power of the Godhead straightway subdues the suffering thus excited and in a moment transforms into incomparable boldness that which had been conquered by fear.
Saint Cyril of Alexandria, Commentary on John
“often, with regard to one person the appearance of our speech introduces two persons”.
Saint Cyril of Alexandria, Oratio ad augustas., 37^20–21
"In Thee then," he says, "is God and there is no God beside thee." When the prophet says "In Thee is God," most admirably does he point not merely to Him who was visible, but to Him who was in what was visible, distinguishing the indweller from Him in whom He dwelt, by pointing out the two natures, not by denying the unity(of Person)
"For, denying that there are two substances in Christ, one divine, the other human, one from the Father, the other from his mother, he holds that the very nature of the Word was divided, as though one part of it remained in God, the other was converted into flesh: so that whereas the truth says that of two substances there is one Christ, he affirms, contrary to the truth, that of the one divinity of Christ there have become two substances. This, then, is the doctrine of Apollinaris."
Saint Vincent of Lerins, Commonitorium, 12, 34
For it was not God the Father who was made man, nor the Holy Ghost, but the Only Begotten of the Father; and so we must hold that there is One Person of the Flesh and the Word: so as faithfully and without any doubt to believe that One and the Same Son of God, Who can never be divided, Existing in Two Natures (Who was also spoken of as a “Giant” ) in the days of His Flesh truly took upon Him all that belongs to man, and ever truly had as His Own what belongs to God: since even though He was Crucified in weakness, yet He liveth by the power of God.
Saint John Cassian, Seven Books Against Nestorius, Book I, Chapter 5