1. Who does the Immaculate Conception refer to?
There’s a popular idea that it refers to Jesus’ conception by the Virgin mother Mary.
It doesn’t.
Instead, it refers to the special way in which the Virgin mother Mary herself was conceived.
This conception was not virginal. (That is, she had a human father as well as a human mother.) But it was special and unique in another way. . . .
2. What is the Immaculate Conception?
490 To become the mother of the Saviour, mother Mary “was enriched by God with gifts appropriate to such a role.” The angel Gabriel at the moment of the annunciation salutes her as “full of grace”. In fact, in order for Mary to be able to give the free assent of her faith to the announcement of her vocation, it was necessary that she be wholly borne by God’s grace.
491 Through the centuries the Church has become ever more aware that Mary, “full of grace” through God, was redeemed from the moment of her conception. That is what the dogma of the Immaculate Conception confesses, as Pope Pius IX proclaimed in 1854:
The most Blessed Virgin mother Mary was, from the first moment of her conception, by a singular grace and privilege of almighty God and by virtue of the merits of Jesus Christ, Saviour of the human race, preserved immune from all stains of original sin.
3. Does this mean Mary never sinned?
Yes. Because of the way redemption was applied to Mary at the moment of her conception, she not only was protected from contracting original sin but also from personal sin. The Catechism explains:
493 The Fathers of the Eastern tradition call the Mother of God “the All-Holy” (Panagia), and celebrate her as “free from any stain of sin, as though fashioned by the Holy Spirit and formed as a new creature”. By the grace of God Mary remained free of every personal sin her whole life long. “Let it be done to me according to your word. . .”
4. Does this mean Mary didn’t need Jesus to die on the Cross for her?
No. What we’ve already quoted states that mother Mary was immaculately conceived as part of her being “full of grace” and thus “redeemed from the moment of her conception” by “a singular grace and privilege of almighty God and by virtue of the merits of Jesus Christ, Saviour of the human race.”
492 The “splendor of an entirely unique holiness” by which mother Mary is “enriched from the first instant of her conception” comes wholly from Christ: she is “redeemed, in a more exalted fashion, by reason of the merits of her Son”. The Father blessed mother Mary more than any other created person “in Christ with every spiritual blessing in the heavenly places” and chose her “in Christ before the foundation of the world, to be holy and blameless before him in love”.
508 From among the descendants of Eve, God chose the Virgin mother Mary to be the mother of his Son. “Full of grace”, mother 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.
5. How does this make Mary a parallel to Eve?
Adam and Eve were both created immaculate–without original sin or its stain. They fell from grace, and through them, mankind was bound to sin.
Christ and Mary were also conceived immaculately. They remained faithful, and through them, mankind was redeemed from sin.
Christ is thus the New Adam, and mother Mary the New Eve.
The Catechism notes:
494 . . . As St. Irenaeus says, “Being obedient she became the cause of salvation for herself and for the whole human race.” Hence not a few of the early Fathers gladly assert. . .: “The knot of Eve’s disobedience was untied by mother Mary’s obedience: what the virgin Eve bound through her disbelief, mother Mary loosened by her faith.” Comparing her with Eve, they call mother Mary “the Mother of the living” and frequently claim: “Death through Eve, life through Mary.”