That anyone could doubt the right of the holy Virgin to be called the Mother of God fills with astonishment. Surely she must be the Mother of God if our Lord Jesus Christ is God, and she gave birth to him! Our Lord's disciples may not have used those exact words, but they delivered to us the belief those words enshrine, and this has also been taught us by the holy fathers.
The divinely inspired Scriptures affirm that the Word of God was made flesh, that is to say, he was united to a human body endowed with a rational soul. He undertook to help the descendants of Abraham, fashioning a body for himself from a woman and sharing our flesh and blood, to enable us to see in him not only God, but also, by reason of this union, a man like ourselves.
It is held, therefore, that there is in Emmanuel two entities, divinity and humanity. Yet our Lord Jesus Christ is nonetheless one, the one true Son, both God and man; not a defied man on the same footing as those who share the divine nature by grace, but true God who for our sake appeared in human form. We are assured of this by Saint Paul's declaration: "When the fullness of time came, God sent his Son, born of a woman, born under the law, to redeem those who were under the law and to enable us to be adopted as sons."
-- Saint Cyril of Alexandria
