The mere fact we humans cannot (yet) know the answers to these questions is not evidence they don't exist, it's merely evidence we cannot yet know/see into other realms. We are continually learning new things, science and otherwise. Our understanding of the world and dimensions, etc. probably does not scratch the surface of all knowable information.
We use technologies and have understandings today, that would appear to be impossible or magical, to persons who lived just 1 or 2 centuries ago. Radar, microwaves, mass destruction weapons, flight, jets, space exploration, microwaves, deep sea diving, combustion engines, telephones, microchips, computer processing, atoms, DNA, cloning, AI, and millions of other inventions or understandings. These things were completely unknown or science fiction at some point, not too long ago. The things we currently don't understand, are extremely complex today but in a century or many centuries will have been solved. Such as other dimensions, time travel, long distance space travel, and so forth. What if, for instance, the energy of your soul or what your "life" represents (and it is something, it's not nothing), is not bound by time, dimensions, or space?
There is a phenomena, only recently observable due to advances in science, where electrons behave differently when viewed. So we, the viewer, can and do impact the real world by merely viewing something.
There are endless, or nearly endless, credible examples of ghosts, spirits, demons, devils, angels, etc. in highly credible texts, interviews, writings, exorcisms, etc. from very credible people. Seems very short sighted, to be a skeptic just because it's not necessarily scientifically repeatable or provable.
It is the skeptic, rather than the believer, who is going to be proven wrong at some point. As I and others have said here, energy cannot be destroyed, so when your life force energy terminates, it must go somewhere. It's highly plausible it goes into another dimension, spirit world, etc. I'm betting on the fact these do exist and we are simply unable to measure them.