Mary is the Virgin Mother of God.

"Just as, in the age of Mary the mother of God, he who had reigned from Adam to her time found, when he came to her and dashed his forces against the fruit of her virginity as against a rock, that he was shattered to pieces upon her, so in every soul which passes through this life in the flesh under the protection of virginity, the strength of death is in a manner broken and annulled, for he does not find the places upon which he may fix his sting." Gregory of Nyssa, On Virginity, 14 (A.D. 370).