I read a book years ago by someone who claims to be a proficient astral traveller (sorry, can't recall the author's name), and he claimed to have visited some plane of existence where he witnessed many people who'd died, and were experiencing a period of time in 'heaven / hell', before they moved on, because they'd believed ardently in that while 'alive', that their minds sort of created it for them.
They'd only progress when they twigged that it was their own creation & imposition of this 'reality', and there were other things they could be exploring instead.
I'm not saying I take it to be factual, but it's interesting to contemplate.
I'd already wondered if the belief of people like my husband, that when you die, that's it, there's nothing else - might actually hinder them from moving on after death. I can picture the scene - a spirit guide appears to lead the way, & he says stubbornly, "No, you're not real & this isn't happening. I'm dead. Sod off!"
My son, on the other hand, got into a flap at having to walk past graves on the school grounds when he first went - kept panicking about not wanting to have to 'live' under a stone when he's dead, and fretting that he wouldn't know where to go & what to do when he dies. He was really scared, & it kept preying on his mind, so I told him that it's nothing to worry about, and I'll come & show him.
That eased his mind, but then his dad said I was filling his head with rubbish. I've always told him to decide about religion(s) when he's old enough to understand them, and not before, but I couldn't stand seeing a tiny boy worrying about death! Not just his own, but mine & his Gran's. So, if it's possible to meet him when he passes over (as I actually suspect it is) I'll be there.