I've had my own experiences with the supernatural and have been intrigued by it since I saw with my own eyes as a child. I do not know if any one religion has it right or not. I tend to take parts from all religions that make more sense to me and sort of lump the best parts together in my own way.
The scientist in me says that matter can neither be created nor destroyed.
I've seen enough evidence to be certain in my own mind that the spirit realm does exist. There are things in this world we cannot see due to our limited visual range. There are things in this world we cannot hear due to our limited audio range. We cannot see infrared or hear subaudible sounds, proven fact, unless we have technology that permits it. I believe we are on the cusp of the technology that will enable us to see and hear the spirit realm, but the question is should we? We are built to see and hear the world in a certain way. Those experiences change the way we behave around others and the actions we take. What if we could hear and see the deceased? What if they had knowledge of things we should not know? There is evil on both sides of the vale. How would we be able to discern the difference? What if we went in search of the unknown and were misled by evil entities who want nothing but our destruction? It could be catastrophic to the future of the human race. What if these limitations were place on us by the divine to keep us relatively safe from these unknown evils? We see how some sciences have given us both good and evil powers we were not meant to have. If the wrong sort were led astray by the evil entities those people could unknowingly destroy the planet or worse. We just don't know. Our curiosity is limitless and there are some things we may be better off not knowing until it is appointed by some higher power.
Do I believe?
Yes. I believe, but I believe in balance as well. Good and evil cannot exist without each other. If you see a spirit, it could be good or evil. There is no way of really knowing which side they are on.
For me it is a fun exercise of the mind to think on from time to time, but ultimately we must live our lives and be prepared to cross over to the other side when it is our time. Hopefully things will be better there, but there is no way of knowing, except through faith.
These are my first, immediate thoughts on the subject. Not quite ready to share my own experiences on here yet.