Ok, first Catholics say Mary was conceived without sin. Then they say she lived without sin and was a virgin all her life. Finally, they say she was assumed body and soul into heaven? Where does the Bible say that? Where do they get this stuff?
First, let’s see what the Catechism has to say on this. What do Catholics really believe?
“Finally the Immaculate Virgin, preserved free from all stain of original sin, when the course of her earthly life was finished, was taken up body and soul into heavenly glory, and exalted by the Lord as Queen over all things, so that she might be the more fully conformed to her Son, the Lord of lords and conqueror of sin and death." The Assumption of the Blessed Virgin is a singular participation in her Son's Resurrection and an anticipation of the resurrection of other Christians: (966 CCC)
There’s a lot there, but the main point is that Mary was completely without sin and as such was assumed body and soul into heaven as an anticipation of the resurrection of other Christians. In other words, what she did is nothing different than what we will do one day when we’re united with our bodies at the end of time. She just gets to go early. To deny the assumption of Mary is similar to denying our own resurrection. Any Christian out there feel like doing that?
Our tradition tells us that she was taken up body and soul into Heaven. “But where is it in the Bible?” you may ask. It’s not.
However, let me tell you about four people who were assumed. Enuch was assumed in Genesis 5. Elisha in 2 Kings 2 was taken up in a chariot of fire. The two witnesses in Revelation 11 ascend into heaven in the sight of all their enemies after being killed. Bodily assumption happens in the Bible, so you can’t deny that it’s possible at the very least.
What about the woman in Revelations 12? The woman with the crown of starts in the heavens who gives birth to a male child? This, we believe, is a sign of Mary body and soul in heaven.
So, we have a precedent set of four other people being assumed, an image of Mary in heaven, tradition from the early church, and no contradictions in the Bible. Why shouldn’t I trust the tradition of my Church? I have no reason not to.