The Roman Catholic Church refers to this feast as the "Immaculate Conception", to affirm that Mary was immaculately conceived in the womb, free of original sin. The Orthodox and Episcopal Church traditions espouse the theology of some ancient theologians who teach that all human beings -- including the Virgin Mary, a human like the rest of us, unlike Jesus who is not only truly human but is also the incarnate Son and Word of God -- are born into a fallen, death-bound, demon-riddled world whose "form is passing away" (1 Corinthians 7:31). We are all born mortal and tending toward sin. Yet, according to this view, humans aren't born guilty of any personal sin, certainly not one allegedly committed "in Adam." Nor are we born "stained" because of the manner in which we're conceived by the sexual union of our parents. Otherwise, if sexual union in marriage is in any sense sinful, or the cause per se of any "stain" of sin, then, as the great Eastern Father St. John Chrysostom has taught, God would be the sinner because God created us this way, male and female, from the beginning.
"Mary is conceived by her parents as we are all conceived. But in her case it is a pure act of faith and love, in obedience to God's will, as an answer to prayer. In this sense her conception is truly "immaculate." And its fruit is woman who remains forever the most pure Virgin and Mother of God."