So why than is a body even needed in Heaven. I can see why in this physical world a body is needed to clothe the soul. But why it's needed in a spiritual place like Heaven, that makes no sense to me. Especially when, as you suggest, body functions cease.
The idea of a "soul" encased in flesh is, fundamentally, a foreign idea to Christianity. Human beings aren't enfleshed souls, they are ensouled bodies. We aren't souls in a body, we are bodies with soul, with the breath of life, more than a dead corpse,
alive; but alive as fully fleshy, solid creatures with bone and tissue.
Which is precisely why Christians have always confessed the resurrection of the body. Because our destination isn't "heaven", but this very world of ours; so yes, we will be bodied creatures here on earth, because that's the Christian hope: Christ will come again, the dead will be raised, and God will make all creation new.
If, however, one believes that we are nothing more than "souls" wearing "earthsuits" that are to be discarded so that we can go dwell in the cloud lands strumming harps as wisps of ethereal something-or-other then, sure, resurrection, bodily existence, and this world itself don't really matter; our "true" existence as spirits in the great spiritual pleroma is all that matters and this present existence is at best a testing ground or at worst a prison.
I don't believe that. I believe this life matters. I believe the things of this world matter. I believe that everything that is good and lovely has permanence--our love for one another, friendships, family, art, the natural beauty, kindness, etc are beautiful, wonderful things and aren't going to disappear forever, lost forever, but have a concrete, real permanence that will never be lost.
-CryptoLutheran