Gregory Nazianzus, in writing to Cledonius regarding the Apollinarian controversy in the mid fourth-century, beautifully states the orthodox theology of Jesus Christ:
For we do not sever the Man from the Godhead, but we lay down as a dogma the Unity and Identity of Person,
Who of old was not Man but God,
and the Only Son before all ages,
unmingled with body or anything corporeal;
but Who in these last days has assumed Manhood also for our salvation;
passible (able to suffer) in His Flesh, impassible in His Godhead;
circumscript (limited) in the body, uncircumscript in the Spirit;
at once earthly and heavenly, tangible and intangible, comprehensible and incomprehensible; that by One and the Same Person, Who was perfect Man and also God, the entire humanity fallen through sin might be created anew.
I’m grateful for the ancient heresies that arose to challenge the Church. It was in the heat of theological battle over the identity of Jesus our Christ that precise, life-giving definition was given and set in stone. We twenty-first century folks are in deep debt to the work of our forefathers in the faith.