1. Why does the Church teach that Mary was immaculately conceived? Her conception is never even mentioned in Scripture.
Before presenting the scriptural foundations for the Church’s belief in Mary’s Immaculate Conception, know that the person who is posing this question to you is probably operating with the three following misconceptions: (1) The doctrine infringes upon the universality of Christ’s redemption and the unique holiness of God. (2) The Church has no scriptural foundation for the teaching. (3) If any doctrine is not in Scripture it must not be true. Any adequate defense of Our Lady’s Immaculate Conception is incomplete unless all three of these areas are addressed.
The first issue that you need to cover is sola scriptura—the idea that the Bible is the only rule of faith. One of the reasons why our separated brethren have difficulty accepting certain Marian teachings is that they do not understand the scriptural role of sacred Tradition and the magisterium.
The Catholic Church was commissioned by Christ to teach all nations and to teach them infallibly—guided, as he promised, by the Holy Spirit until the end of the world (see John 14:25, 16:13). The mere fact that the Church teaches that something definitely true is a guarantee that it is true (see Luke 10:16).
Besides historical evidence and the authority of Tradition, several biblical texts can be offered. In Genesis 3:15, God states that there is to be an enmity between the “woman” and the serpent, and this enmity is shared between her seed and its seed. Her seed is the messiah, who stands in opposition to the seed of the serpent. The mother of the messiah is said to share the same enmity—total opposition—with Satan.
If Mary, “the woman,” had any sin, then she would not be in complete opposition to the devil. Some argue that the “woman” refers to Eve, but this can not be the complete meaning of the text, as Eve is always associated with her collaboration with the serpent, not her opposition to him. Only Mary, the new Eve, fits the description of the woman in Genesis 3:15.
An implicit reference can also be found in the angel’s greeting to Mary in Luke 1:28: “Hail, full of grace, the Lord is with you.” The phrase “full of grace” is a translation of the Greek word kecharitomene. This word represents the proper name of the person being addressed by the angel, and it therefore expresses a characteristic quality of Mary. Kecharitomene is a perfect passive participle of charitoo, meaning “to fill or endow with grace.” Since this term is in the perfect tense, it indicates a perfection of grace that is both intensive and extensive.
This means that the grace Mary enjoyed was not a result of the angel’s visit, and was not only as “full” or strong or complete as possible at any given time, but it extended over the whole of her life, from conception onward. She was in a state of sanctifying grace from the first moment of her existence to have been called “full of grace.”
Over the centuries, the Fathers and doctors of the Church spoke often about the fittingness of the privilege of Mary’s Immaculate Conception. The dogma is especially fitting when one examines the honor that was given to the Ark of the Covenant. It contained the manna (bread from heaven), stone tablets of the Ten Commandments (the word of God), and the staff of Aaron (an instrument of Israel’s redemption).
If this box was created with such honor—to carry a stick, some bread, and stone tablets—how much more should Mary be made a worthy dwelling place for God himself? She is the new Ark of the Covenant because she carried the real bread from heaven, the Word of God, and the instrument of our redemption, Jesus’ body.
Some argue that the new ark is not Mary but the body of Jesus. Even if this were the case, it is worth noting that 1 Chronicles 15:14 records that the persons who bore the ark were to be sanctified. There would seem to be no sense in sanctifying men who carried a box and not sanctifying the womb who carried the Holy One himself. After all, wisdom will not dwell “in a body under debt of sin” (Wis. 1:4 [NAB]).
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