Tom
I think you are right to some exten, we don't KNOW at all. And I do agree with the thought that the people who do say they KNOW are loony at best and scary and dangerous and destructive at worst.
I have very personal beliefs but still many doubts. I do NOT believe in organized religion because I think it leads to the fundamentalism that destroys and kills and hates.
But I also do not believe in the people that say these things do NOT exist, that there is NO supernatural events. The there are no spirtis or another plane of existence. I am not sure if I totally believe in these things, but I will not discount their existence.
I think there is an atheistic fundamentalism as well, that is just as dangerous as religious fundamentalism.
I have had experiences that I cannot explain (My grandmother visited me before she died, I am convinced of this. And I have had other "visitations" as well. AM i deluded, I don't think so. Can I explain it, NO, but I am convinced it happened.)