i've read a number of books on the para normal. tale after tale of people's real experiences with the dead, with their own near-death, trips out of body, religious or ecstatic visions and visitors.
in some the point is to convince us these things happen, and that they are quite common. sometimes the conclusion is they must therefore be real.
in some, it's just part of someone's story, like Hildegarde of Bingham's visions and revelations, taking at face-value that they are from god.
and i read Mary Roach's "Spook" -- her scientific investigation into ghosts and after-death experiences. lots to laugh about and be amazed by, but no final answers to be found.
i just finished Oliver Sacks' "Hallucinations" which covers some of the same territory from a neurological point of view, appropriately not considering any other possible explanation. he begins with simple hallucinations in some blind people (Charles Bonnet syndrome), easily understood as the brain's reaction to loss of vision. then he leads us on further into various phenomenon not so clearly explained neurologically, but then goes on to explain them now that we are primed to hear such views.
so he tells of patients with ecstatic religious visions, hearing of celestial voices, seeing deceased loved ones, having out of body experiences, and gives us the details of how the brain is bringing all this about. he ends with the neurological explanation for the not uncommon feeling of a presence, that we are not alone, in a helping way or in a threatening way, and he surmises that this leads humans to the idea of god.
round and round we humans go trying to understand our experiences and our brains, using our experiences and our brains -- each expert feeling a different part of the elephant. (you know the elephant story i'm sure). my conclusion so far...it's all hallucination!