CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 506–509

506 Mary is a virgin because her virginity is the sign of her faith "unadulterated by any doubt", and of her undivided gift of herself to God's will. It is her faith that enables her to become the mother of the Savior: "Mary is more blessed because she embraces faith in Christ than because she conceives the flesh of Christ."
507 At once virgin and mother, Mary is the symbol and the most perfect realization of the Church: "the Church indeed. . . by receiving the word of God in faith becomes herself a mother. By preaching and Baptism she brings forth sons, who are conceived by the Holy Spirit and born of God, to a new and immortal life. She herself is a virgin, who keeps in its entirety and purity the faith she pledged to her spouse."
508 From among the descendants of Eve, God chose the Virgin Mary to be the mother of his Son. "Full of grace", Mary is "the most excellent fruit of redemption" (SC 103): from the first instant of her conception, she was totally preserved from the stain of original sin and she remained pure from all personal sin throughout her life.
509 Mary is truly "Mother of God" since she is the mother of the eternal Son of God made man, who is God himself.