That anyone could doubt the right of the holy Virgin to be called the Mother of God fills me 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. In the third book of his work on the holy and consubstantial Trinity, our father Athanasius, of glorious memory, several times refers to the holy Virgin as “Mother of God.” I cannot resist quoting his own words: “As I have often told you, the distinctive mark of holy Scripture is that it was written to make a twofold declaration concerning our Savior; namely, that he was and has always been God, since he is the Word, Radiance and Wisdom of the Father; and that for our sake in these latter days he took flesh from the Virgin Mary, Mother of God, and become human.”

—Letter 1 (ca. mid-5th century)