Is the Church 100% sure that Mary died, as we know death, before she was Assumed into Heaven, If so, why was that necessary since she was Immaculate. God Bless, Memaw
by the authority of our Lord Jesus Christ, of the Blessed Apostles Peter and Paul, and by our own authority, we pronounce, declare, and define it to be a divinely revealed dogma: 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.
Note the Pius XII only declared that Mary had completed her earthly life. There is no mention as to if this meant death (as we know it) or if Mary was assumed while still alive. Catholics are thus free to hold either opinion.