I got this from a fundamentalist website, please explain it.
Today’s Question: The virgin Mary was conceived without sin, so God is evermore present within her and that is why she did not sin on earth though she was human–and it is impossible to sin when filled with the Spirit–the angels who sinned were on a probationary period they could and did sin a great sin which put some into hell. But the other angels have no possibility of doing this and for the same reason the blessed virgin has no possibility of doing this. *
[left]Janice Rathburn *
Bible Answer: Concerning Mary not sinning. The Bible clearly tells us that she sinned. She called God her savior. “And Mary said: My soul glorifies the Lord and my spirit rejoices in God my savior” (Luke 1:46). You only need a savior if your need saving. Mary needed saving like everyone else. The Bible also records a great sin by Mary. She doubted her son’s mission.
Mark 3:21 says, "When his family heard about this, they went to take charge of him, for they said, “He is out of his mind.”
Did Jesus family who thought that He was crazing include Mary? It sure did because later in that same chapter it says,
Then Jesus’ mother and brothers arrived. Standing outside, they sent someone in to call him. A crowd was sitting around him, and they told him, “Your mother and brothers are outside looking for you.” “Who are my mother and my brothers?” he asked. Then he looked at those seated in a circle around him and said, “Here are my mother and my brothers! Whoever does God’s will is my brother and sister and mother” (Mark 3:31-35)
So it’s clear that Mary committed the sin of doubt. As the Bible says, "everything that does not come from faith is sin. (Rom 14:23).
Another way to prove that Mary was not born without the stain of original sin, simply look at Luke 2:21-24:
On the eighth day, when it was time to circumcise him, he was named Jesus, the name the angel had given him before he had been conceived. When the time of their purification according to the Law of Moses had been completed, Joseph and Mary took him to Jerusalem to present him to the Lord (as it is written in the Law of the Lord, “Every firstborn male is to be consecrated to the Lord”), and to offer a sacrifice in keeping with what is said in the Law of the Lord: “a pair of doves or two young pigeons.”
Who was the sacrifice of sins made for? Lev 12:6-7 clearly says that the sacrifice was for the mother.
"'When the days of her purification for a son or daughter are over, she is to bring to the priest at the entrance to the Tent of Meeting a year-old lamb for a burnt offering and a young pigeon or a dove for a sin offering. He shall offer them before the LORD to make atonement for her, and then she will be ceremonially clean from her flow of blood. "'These are the regulations for the woman who gives birth to a boy or a girl.
Now Janice, I think that you are a reasonable person. How do you answer these verses and still hold to the Catholic doctrine of the immaculate conception?