The Chalcedonian Definition
Council of Chalcedon · 451
The decisive statement of how Christ is one person in two natures, fully divine and fully human, without confusion or division.
Following the holy fathers, we all with one voice teach that our Lord Jesus Christ is to us one and the same Son, the self-same perfect in Godhead, the self-same perfect in manhood; truly God and truly man.#
The self-same 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, sin only excepted.#
“One and the same Christ, Son, Lord, Only-begotten, to be acknowledged 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 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.#