Just to clarify things a little, I do not have any doubts about the existence of a 'spirit world', but I am uncertain of its true nature.
I do not believe that it would be a good thing for science to prove the existence of this 'spirit world'. Science, to me, strips emotion and magic out of our world, leaving it a coldly clinical place to live in. So I, for one, am quite happy with scientists (I use the term broadly) dismissing the 'spirit world' as imaginary, psychological, poppycock, or whatever. As long as they continue to do that, they will leave the 'spirit world' alone, and the rest of us can continue to experience it as best we may.
Some years ago, an elderly, devout Christian lady asked me if I believed in a God. My answer was, and still is: emotionally, yes; intellectually, no.