Chalcedonian Definition

Therefore, following the holy fathers, we all with one accord teach men to acknowledge one and the same Son, our Lord Jesus Christ, at once complete in Godhead and complete in manhood, truly God and truly man, consisting also of a reasonable soul and body; of one substance with the Father as regards his Godhead, and at the same time of one substance with us as regards his manhood; like us in all respects, apart from sin; as regards his Godhead, begotten of the Father before the ages, but yet as regards his manhood begotten, for us men and for our salvation, of Mary the Virgin, the God-bearer; one and the same Christ, Son, Lord, Only-begotten, recognized in two natures, without confusion, without change, without division, without separation; the distinction of natures being in no way annulled by the union, but rather the characteristics of each nature being preserved and coming together to form one person and subsistence, not as parted or separated into two persons, but one and the same Son and Only-begotten God the Word, Lord Jesus Christ; even as the prophets from earliest times spoke of him, and our Lord Jesus Christ himself taught us, and the creed of the fathers has handed down to us.

Ἑπόμενοι τοίνυν τοῖς ἁγίοις πατράσιν ἕνα καὶ τὸν αὐτὸν ὁμολογεῖν υἱὸν τὸν κύριον ἡμῶν Ἰησοῦν Χριστὸν συμφώνως ἅπαντες ἐκδιδάσκομεν, τέλειον τὸν αὐτὸν ἐν θεότητι καὶ τέλειον τὸν αὐτὸν ἐν ἀνθρωπότητι, θεὸν ἀληθῶς καὶ ἄνθρωπον ἀληθῶς τὸν αὐτὸν, ἐκ ψυχῆς λογικῆς καὶ σώματος, ὁμοούσιον τῷ πατρὶ κατὰ τὴν θεότητα, καὶ ὁμοούσιον τὸν αὐτὸν ἡμῖν κατὰ τὴν ἀνθρωπότητα, κατὰ πάντα ὅμοιον ἡμῖν χωρὶς ἁμαρτίας· πρὸ αἰώνων μὲν ἐκ τοῦ πατρὸς γεννηθέντα κατὰ τὴν θεότητα, ἐπ᾽ ἐσχάτων δὲ τῶν ἡμερῶν τὸν αὐτὸν δἰ ἡμᾶς καὶ διὰ τὴν ἡμετέραν σωτηρίαν ἐκ Μαρίας τῆς παρθένου τῆς θεοτόκου κατὰ τὴν ἀνθρωπότητα, ἕνα καὶ τὸν αὐτὸν Χριστόν, υἱόν, κύριον, μονογενῆ, ἐκ δύο φύσεων [ἐν δύο φύσεσιν], ἀσυγχύτως, ἀτρέπτως, ἀδιαιρέτως, ἀχωρίστως γνωριζόμενον· οὐδαμοῦ τῆς τῶν φύσεων διαφορᾶς ἀνῃρημένης διὰ τὴν ἕνωσιν, σωζομένης δὲ μᾶλλον τῆς ἰδιότητος ἑκατέρας φύσεως καὶ εἰς ἓν πρόσωπον καὶ μίαν ὑπὸστασιν συντρεχούσης, οὐκ εἰς δύο πρόσωπα μεριζόμενον ἢ διαιρούμενον, ἀλλ᾽ ἕνα καὶ τὸν αὐτὸν υἱὸν καὶ μονογενῆ, θεὸν λόγον, κύριον Ἰησοῦν Χριστόν· καθάπερ ἄνωθεν οἱ προφῆται περὶ αὐτοῦ καὶ αὐτὸς ἡμᾶς ὁ κύριος Ιησοῦς Χριστὸς ἐξεπαίδευσε καὶ τὸ τῶν πατέρων ἡμῖν καραδέδωκε σύμβολον.