Genuine belief: I think we already have an excellent example of what the afterlife is like- try remembering what your experiences were like in the 14-odd billion years the universe existed before you were born.
Lots of fascinating thoughts and philosophy and experimentation and readings on all this stuff. I was deep into it during college and a lot of my 20s. I got back into it a bit during the pandemic year (I'm 50 now), mostly spurred by reading "Consciousness and the Brain" by Stanislas Dehaene (a fantastic, science-based look into what we have figured out about consciousness). Plus turning 50 makes you realize the 20 year old version of yourself really is a whole different person. Not to mention parenting, and how your 12 year old is absolutely a different human than when he was 5, and seeing them realize it. Life is weird.