Upvote:0
We will have "new" bodies, which, not being made of earthly "flesh and blood", will be incorruptible. That is, they will not be subject to disease and deterioration, as mortal bodies are. Thus they cannot die—as these bodies are immortal, they cannot be separated from our spirit, because death is the only thing that can separate body and spirit. All this is explained by Alma. If I have more time later, I will find the relevant chapters/verses.
Upvote:1
I suppose this is not what you want to hear, but:
The separation of spirit and body is death. That means immortality implies that spirit and body will not be separated again. Resurrection makes us immortal.
This is the logic I would follow: Resurrection -> body immortal -> spirit & body inseparable Instead of what seems to be your logic: Resurrection -> spirit & body inseparable -> body immortal
As to what makes us immortal: no clue