“The Apostle tells us: The Word took to himself the sons of Abraham, and so had to be like his brothers in all things. He had then to take a body like ours. This explains the fact of Mary’s presence: she is to provide him with a body of his own, to be offered for our sake. Scripture records her giving birth, and says: She wrapped him in swaddling clothes. Her breasts, which fed him, were called blessed. Sacrifice was offered because the child was her firstborn. Gabriel used careful and prudent language when he announced his birth. He did not speak of “what will be born in you” to avoid the impression that a body would be introduced into her womb from outside; he spoke of “what will be born from you” so that we might know by faith that her child originated within her and from her. . . .
“What was born of Mary was therefore human by nature, in accordance with the inspired Scriptures, and the body of the Lord was a true body: It was a true body because it was the same as ours. Mary, you see, is our sister, for we are all born from Adam.” — From a letter by Saint Athanasius, bishop