Did Mary die? What does her assumption into heaven mean?

Pope Pius XII solemnly defined in Munificentissimus Deus on Nov. 1, 1950, that the "Immaculate Mother of God, the ever-virgin Mary, having completed the course of her earthly life, was assumed body and soul into heavenly glory."1 This document declared the Assumption as an infallible doctrine. This is a belief that had been commonly held by Catholics for many centuries.

As the mother of Jesus, she was assumed into heaven, free from Original sin, immaculate from her conception. Therefore because of her purity and her role as the Mother of God, there could be no corruption of her body, and it was assumed into heaven. This belief was held as far back as the early centuries.

There is an ancient tradition called the Dormition of Mary which means that she fell asleep in the hands of the Lord, and woke up in Heaven. This theory believed by some theologians came to be, out of eminent respect for who she was, and remains today as Mary the Immaculate Mother of Christ, and Mother of all. Exactly how Mary died is still debatable and not definitely known.

In 1973, the National Conference of Catholic Bishops, in their letter "Behold Your Mother", stated, "Christ has risen from the dead, we need no further assurance of our faith. Mary assumed into heaven serves rather as a gracious reminder to the Church that our Lord wishes all whom the Father has given Him to be raised with Him. In Mary taken to glory, to union with Christ, the Church sees herself answering the invitation of the heavenly Bridegroom."

"She is the symbol of God's final victory in humanity. In her bodily Assumption, we know that all of our humanity is free, redeemable and of immeasurable dignity. It happened in her in accelerated and perfect fashion so we could look at her and say, "Yes." She is one of us and she is what we will be. We now know that the resurrection Jesus has promised will also be given to us in spirit and in body."2

1. http://www.papalencyclicals.net/Pius12/P12MUNIF.HTM

2 .Richard Rohr - Great Themes of Scripture