I believe in a core identity or spirit which is distinct from the personality (pneuma rather than psyche to be technical). I believe that this remains and therefore people should be treated with as much respect and dignity as possible, including addicts and victims of dementia. But relationships are primarily with the person, and that gets hard.
I heard a preacher recently talking about heaven "up there" ... saying nothing very meaningful to me. I believe in a resurrection "down here", when Jesus returns and heaven comes down to earth. When this earth is renewed, when injustice and hatred are replaced by love and justice, then we too will be raised and renewed - to be the people we really are, deep, deep down inside.
Part of who we really are lies in our deepest and truest relationships, so I expect to see those restored too. Although not necessarily as we expect: imagine someone we have only known as a quiet old grandma resurrected as a lively young flapper!
Now imagine someone you know who is self-obsessed and treats others appallingly. Maybe s/he has always been like this, or maybe they have become so because of things that have happened to them, or through bad choices they have made. Unless and until we meet them post-resurrection we have no way of knowing who they really are; although God does.
This post is turning shapeless, but I think there is something in here that I do want to say. Anyway it's a while since I did a 'ramble' post, so I'll adjust the title a little ;-)