Pope St. Leo the Great, Letter to Flavian, read and received at the Council of Chacedon, the 4th Ecumenical Council: “Overcoming the originator of sin and death would be beyond us, had not he whom sin could not defile, nor could death hold down, taken up our nature and made it his own. He was conceived from the holy Spirit inside the womb of the virgin mother. Her virginity was as untouched in giving him birth as it was in conceiving him.”