I didn't read all posts up to this point, but read about half, and then figured I'd make a few points.
About consciousness. Let's play a science fiction experiment...say we store your memories in a computer, and tell you that you're going to be killed. We're going to "bring you back" as a copy of yourself, a clone that is indistinguishable from you in every way, and it will have all your memories. It sounds maybe a little terrifying. But should you really be afraid? After all, it will be just like you, and essentially you. It will even remember having this conversation. It will wake up in a bed (the same bed we put you down in). The copy will remember everything, it will experience having woken up...but you will not. You will die, and will be gone. The first line below is you, the second line is your copy. X is death. ---- is lived experience, () is implanted memory.
-----X
(-----)X----->
So what significance did "you" have in the first place? You technically died, and are gone forever, but there's someone identical to you in every conceivable way still here. So did you really die? This ties into issues of identify and consciousness.
Now think of this (many already know this one): every 8 years or so, according to science, the cells of the body copy themselves (are regenerated). This is similar to the science fiction thought experiment, right? Are we really who we used to be? Maybe, maybe not. The passage of time is itself like death at every new point. We cannot necessarily distinguish where one "thing" ends and another begins. Things die and are remade, transferred to new energy forms, etc etc all the time. Sometimes they persist with "continuity", but between continuity is nothingness. Most of the universe is nothingness.
So. Maybe a billion years pass and there's a new you after you die. That time might as well be a blink of an eye to "you" (like before you were around, time passed very quickly, did it not?). At some point something was born of nothingness. How did this happen? We can project where the universe is headed (back to nothingness)...will it then start again, with something out of nothingness? It's quite possible. In a sense, time has no real meaning without consciousness anyway.
Our consciousness (as we understand it, linked to our identity) to me seems specific to this body and this life, like being encapsulated within the brain and the body. There are myths and stories of course...and some ambiguity about "what might have happened" or "what will happen", especially explored in religion...but I see them as stories more than anything, like stories in a storybook. Why should we believe they're anything other than made up except that people are claiming them to be such, if we cannot validate them for ourselves? People have shown us time and time again that they will lie. They will lie, they will imagine things, they are not reliable. So I think it's safe to not believe in comforting stories, myths, etc. about the afterlife. If something sounds crazy to me, I will discount it unless there's evidence. But I keep an open-mind because the universe seems to contain a fascinating infinitude of unknowns. We'll continue to make breakthroughs in science and technology and reach higher understandings of what it all means...and help to correct myths, lies, illusions, etc in the process.