We believe in one God, the Father Almighty, Maker of ​heaven and earth, and of all things visible and invisible; And ​in one Lord Jesus Christ, the Son of God, the Only-​begotten, Begotten of the Father before all ages, Light of ​Light, Very God of Very God, Begotten, not made; of one ​being with the Father, through whom all things were made:

Who for us men and for our salvation came down from ​heaven, and was incarnate of the Holy Spirit and the Virgin ​Mary, and was made man;

And was crucified also for us under Pontius Pilate, and ​suffered and was buried;

And the third day He rose again, according to the ​Scriptures; And ascended into heaven, and sits at the right ​hand of the Father;

And He is again coming with glory to judge the living and ​the dead, Whose kingdom shall have no end.

And in the Holy Spirit, the Lord, and Giver of Life, Who ​proceeds from the Father and the Son, Who with the Father ​and the Son together is worshipped and glorified, Who ​spoke by the Prophets; in one, holy, catholic, and apostolic ​Church. We acknowledge one baptism for the remission of ​sins. We look for the resurrection of the dead, And the life ​of the age to come. Amen.

The Nicene-Constantinopolitan Creed (381 AD)

We, then, following the holy Fathers, all with one consent, ​teach men to confess one and the same Son, our Lord ​Jesus Christ, the same perfect in Godhead and also ​perfect in manhood; truly God and truly man, of a rational ​soul and body; consubstantial with the Father according to ​the Godhead, and consubstantial with us according to the ​Manhood; in all things like unto us, without sin; begotten ​before all ages of the Father according to the Godhead, ​and in these latter days, for us and for our salvation, born ​of the Virgin Mary, the Mother of God, according to the ​Manhood; one and the same Christ, Son, Lord, only ​begotten, to be acknowledged in two natures, ​inconfusedly, unchangeably, indivisibly, inseparably; the ​distinction of natures being by no means taken away by ​the union, but rather the property of each nature being ​preserved, and concurring in one Person and one ​Subsistence, not parted or divided into two persons, but ​one and the same Son, and only begotten, God the Word, ​the Lord Jesus Christ; as the prophets from the beginning ​[have declared] concerning Him, and the Lord Jesus ​Christ Himself has taught us, and the Creed of the holy ​Fathers has handed down to us.

Definition of Chalcedon (451 AD)