From: the apostolic constitution “Munificentissimus Deus” by Pope Pius XII
In their homilies and sermons, the holy fathers and great doctors spoke of the assumption of the Mother of God as something already familiar and accepted by the faithful. They brought out more clearly the fact that what is commemorated is not simply the total absence of corruption from the dead body of the Blessed Virgin Mary but also her triumph over death and her glorification in heaven, aster the pattern set by her only Son Jesus Christ.
Scripture portrays the loving Mother of God, almost before our very eyes, as most intimately united with her divine Son and always sharing in his destiny. Above all, from the second century the holy Fathers present the Virgin Mary as the new Eve, most closely associated with the new Adam, though subject to him in the struggle against the enemy from the nether world. This struggle was to end in perfect victory over sin and death.
“It was necessary that she who had preserved her virginity inviolate in childbirth should also have her body kept free from all corruption after death. It was necessary that she who had carried the Creator as a child on her breast should dwell in the tabernacles of God. It was necessary that the bride espoused by the Father should make her home in the bridal chambers of heaven. It was necessary that she, who had gazed on her crucified Son and been pierced in the heart by the sword of sorrow which she had escaped in giving him birth, should contemplate him seated with the Father. It was necessary that the Mother of God should share the possession of her Son, and be venerated by every creature as the Mother and handmaid of God.” Saint John Damascene.
The august Mother of God, mysteriously united from all eternity with Jesus Christ in one and the same decree of predestination, immaculate in her conception, a virgin inviolate in her divine motherhood, the whole-hearted companion of the divine Redeemer who won complete victory over sin and its consequences, gained at last the supreme crown of her privileges—to be preserved immune from the corruption of the tomb, and, like her Son, when death had e conquered, to be carried up body and soul to the exalted glory of heaven, there to sit in splendor at the right hand of her Son, the immortal King of the ages.