Mary was the mother of Jesus. His flesh was formed from her flesh, thus making him truly a man and descendant of Adam and Eve.
Mary, by the grace of God and not only by her own human nature, remained without sin her entire life, as maintained by both Catholics and Orthodox. She was, as maintained in both traditions, a new type of Eve. She said “yes” to God rather than “no.” She is the archetype of the Church.
Mary remained a perpetual virgin throughout her life, as maintained in both the East and West. She did not have relations with Joseph. Consider that her womb was a tabernacle of the Lord, that God overshadowed her as He did the Ark, and that in her womb she carried the High Priest, the Law/Word, and the Bread of Life, similar to the Ark of the Covenant, which carried Aaron’s staff, the tablets of the Ten Commandments, and the manna. She served as the Ark of the New Covenant, by her own will and by the grace of God. Consider the reverence the Israelites gave the Ark and the Holy of Holies in the Temple, and it’s easy to see why a righteous man of God such as Joseph would understand that she had been set apart to serve God, and that he’d respect that.
Mary is the Mother of God, or theotokos, because she is Jesus’ mother, and Jesus was God from the moment of his conception, and the human and divine natures are united in Jesus as one person, not two, and Mary is the mother of a person, not a nature.
Mary was without sin her whole life, and was always blessed and graced by God, as implied by the title kecharitomene, which is how the angel addressed her. And, as an archetype of the Church, God made her “holy, cleansing her by the washing with water through the word, and to present her to himself as a radiant church, without stain or wrinkle or any other blemish, but holy and blameless (Eph 5).” This is understood as the Immaculate Conception, for out of love for his mother, and to prepare her to accept the Incarnation without any reservation that sin might cause, he filled her with grace and justified her from the instant of her conception, not by any merit of her own, but from the merits of Christ Jesus, for God is not bound by time.
Mary, as believed by both the East and the West, at the end of her life, was herself assumed (not ascended like Jesus, but assumed) into Heaven and made Queen of Heaven, not as its sovereign, but similar to the Queen Mother of ancient Israel and Judah, herself subject to her son, the King.
And, like all saints in Heaven, they are works of God and our elder brothers and sisters in Christ, those who have gone before and watch us like a cloud of witnesses, striving to pray for us, as we are one body in Christ, and lead us to God.
