I suppose it's rather speculative. And there are quite diverse belief systems amongst us all.

I for one rejected the religion I was brought up on (Mormonism), and in doing so, felt that meant there was no God or spirit world. Funny how it can seem so either/or until you learn to think differently.

Thankfully at some point it occurred to me that there could still be a spirit world without my having to fit it within the definition of any specific religion. Whew.

Having found and interacted with spirits through photography and clairaudience, I have been able to see many of the links to various religions and belief systems. It seems to me that there is some truth in all beliefs. For me, instead of finding religion to validate spirituality, I have found spirituality to validate religion.