Luther’s “take” on this:
Today the festival of our dear lady, the mother of God, is observed to celebrate her death and departure above. But how little this Gospel corresponds with this is plain. For this Gospel tells us nothing about Mary being in heaven. And even if one could draw from this text every detail about what it is like for a saint to be in heaven, it would be of little use. It is enough that we know that departed saints live in God, as Christ concludes in Matthew [Matthew 22] based on the passage in Exodus [Exodus 4] where God says to Moses, “I am the God of your fathers, the God of Abraham, the God of Isaac and the God of Jacob,” that God is not the God of the dead, but the God of the living.
These passages sufficiently prove that they live. But we should not try to figure out what their life is like up there for it is not necessary for us to know. It is also not necessary to discover it. Reason is incapable of it. Some great masters have understanding about some things and yet not about this. For there are three states of life. First, as a child lays in his crib he lives in God but hardly perceives it Second, when we sleep we also are alive and are scarcely aware of it. Thirdly, when we definitely are aware and experience that we are living, even then we don’t know how.
Now since here on earth God deals with us in this meager prison (that is barely half a life), in such a way that we barely perceive how we live here, how much more can He give life in heaven where it is spacious and where is true life. So we cannot set up any definite limits or establish a rule as to how the saints live there since even here dreaming and crazy people live, but we can’t imagine how. It is enough to know that they live. But it is not necessary for us to know what that life is like. That is why I have always said that our faith always must rest upon what is known. We do not make articles of faith out of what doesn’t rest squarely on Scriptures, else we would daily make up new articles of faith. For this reason, those things that are necessary to believe which you must always preserve, which Scripture clearly reveals, are to be markedly distinguished from everything else. For faith must not build itself upon what Scripture does not clearly prove. So since the Scripture clearly says here that Abraham, Isaac, Jacob and all believers live, then it is necessary for you to believe that the mother of God lives. You can leave it in our gracious God’s hands what that life is like. Enough said about this festival. [Festival Sermons of Martin Luther (Michigan: Mark V Publications, 2005) pp. 145-14].
Here is an interesting factoid for you:
Just like Pope Frankie, Luther is not infallible.
Plus Luther is not our “Pope.”
If it were not for those pesky chapter-and-verse Prots, we could expect Rome would come up with more traditions of men being taught as doctrines.