This creed was adopted at the Fourth Ecumenical Council held at Chalcedon–located in what is now Turkey–in 451 as a response to certain heretical views concerning the nature of Christ. It established the orthodox view that Christ has two natures (human and divine) that are unified in one person.
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 reasonable 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, unconfusedly, 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.
This creed builds some very important parameters around the person of Christ and the Trinity. To best explain the contribution of this creed I have borrowed a very helpful diagram that seeks to do just that. The diagram below is called the Chalcedonian Box. It captures the boundary markers for thinking about the person of Christ. Orthodox Christology falls within these parameters.
