Definition of Chalcedon
Following, then, the holy fathers, we unite in teaching all men to confess the one and only Son, our Lord Jesus Christ. This selfsame one is perfect both in deity and in humanity; this selfsame one is also actually God and actually man, with a rational soul and a body. He is of the same reality as God as far as his deity is concerned and of the same reality as we ourselves as far as his humanity is concerned; thus like us in all respects, sin only excepted. Before time began, he was begotten of the Father, in respect of his deity, but yet as regards his humanity begotten, for us men and for our salvation, of Mary the virgin, the God-bearer [Gr. theotokos]; one and the same Christ, Son, Lord, Only-begotten, 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 Word of God, 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.