Theotokos - Mother of God
The first revealed truth about Mary, and the one from which all others flow, is that she is the mother of Jesus Christ who is God, the second person of the Holy Trinity made man. This is explicitly stated in Luke, “Behold, you shall conceive in your womb and shall being forth a son, and you shall call his name Jesus…; therefore the holy one who shall be born of you shall be called Son of God.” The Council of Ephesus defined Mary as Theotokos, and in doing so protected the revealed truth that Jesus is one divine person with two natures, and the two natures are inseparably united in one person. If we understand that Mary is not the mother of the human person of Jesus, but is the mother of God, we see that Jesus can only be one person. It is fitting that Jesus’ mother who protected him during his life on earth also protects the revealed truth about him.
Immaculate Conception
The second Marian doctrine proclaims that Mary was conceived with no stain from Original Sin. When the Angel Gabriel greeted Mary by saying “Hail, full of grace, the Lord is with you” he is referring to a fullness of grace that is part of Mary’s very nature. No person with a fallen nature could possess a fullness of grace, this is only appropriate for the immaculate woman who was to give the Son of God his immaculate human nature. This dogma is often misunderstood as beginning with Pope Pius IX’s declaration in 1854, but he was only declaring what had been referred to by the Fathers of the Church and later during the first millennium of the Church.
Perpetual Virginity
The third doctrine regarding the Blessed Virgin proclaims that Mary was always a virgin: before, during, and after the birth of Jesus Christ. Mary’s virginity before the birth of Jesus is well documented by scripture. The prophesy of Isaiah states “Behold a virgin shall conceive…a Son”; in the Gospel of Luke the Angel Gabriel was sent “to a virgin…and the virgin’s name was Mary.” The second aspect of the doctrine refers to Mary’s virginity during the birth of Jesus. St. Thomas Aquinas writes of Christ’s miraculous birth: “Painlessly, and without change in Mary’s virgin body, her Son emerged from the tabernacle of her spotless womb, as He was later to emerge from the tomb, without moving stone or breaking the seal of Pilate.” As light passes through glass, so did the Son of God pass out of Mary’s womb. The last aspect of the doctrine is Mary’s virginity after the birth of Jesus. Again, Thomas Aquinas lends his wisdom to understanding God’s plan in saying that Jesus is the only-begotten son of God, so likewise when he became human, he deserved to be the only-begotten son of Mary. The virginal womb of Mary was the shrine of the Holy Spirit; a human conception after Jesus’ divine conception would not respect the tabernacle of the Holy Spirit.
The Assumption of Mary
The fourth Marian doctrine is the Assumption of Mary into heaven. In 1950 Pope Pius XII defined the Assumption of Mary in the statement “The Immaculate Mother of God, the ever Virgin Mary, having completed the course of her earthly life, was assumed body and soul into heavenly glory.” Like the first three doctrines concerning Mary, her Assumption also takes root in scripture: "I will put enmity between you and the woman, between your seed and her seed…” (Gen 3:15). According to St. Paul, the consequences of evil are sin and death, bodily corruption. Therefore Mary, who was conceived without sin and shared in her Son’s victory over Satan, would have been saved from both sin and death. In this we see that the Immaculate Conception and the Assumption are closely linked. In the Immaculate Conception, Mary was preserved from sin; in her Assumption she was preserved from death. Here, the question may be asked: did Mary die before she was assumed? The Catholic Church understands death as the separation of soul and body at the end of earthly life. The Church has never defined whether or not at the end of Mary’s life on earth she experienced some temporary separation of soul and body, but many theologians believe that she did so as to enter Heaven in a manner that most closely resembled her son.