This came up in coversation today briefly and I figured I would explain here as so many people seem to be unsure.
Im going to divide this into 3 sections one for each.
-what definetly won't happen when you die.
-what most likely will happen.
-what is not out of the realm of possibility.
Part I (faith) What definetly will not happen when you will die:
You will not go to heaven, but don't fret as you will not go to hell either. In fact its 100% fact that any "religion" based account of the afterlife is absolutely false. How do I know this? Well its relatively simple if you think about it. There are several thousand religions in this planet some extinct, some still practiced. All believe their own beliefs are the only path to salvation. Since all of them cannot be true, and there is no emprical evidence to support any of them, its pretty safe to say none of them are. Most of them made up thousands of years ago to explain things that science could not. Many of these things have since been explained, like the Sun, moon etc. And from a christian standpoint "God" certainly would not create all these children in his image only to send the vast majority to hell, remember even competing denominations ofthe christian churches think the others are going to hell. Religion does nothing for us anymore, all of its good points have been absorbed into the secular governments (do not steal, ,kill etc) and all that is left is the faith closing the mind to hope and reason.(but this isnt about religion that's another topic).
Part II (reason)- What will most likely happen when you die - You will die. You will cease to exist. Its a pretty crappy deal, but if you think about it, it makes the most sense. As you have no conscience recollection from the beginning of the universe to now, you most likely will not have any recollection of any of the time that happnes after you die. Even if you continue to exist with no recollection of your memories here on earth, the person you are here is still effectively dead. Our memories make us who we are. People have a starting point (birth), things that are infinite dont have a starting point or an ending point for that matter.
Part III (hope) - What is not out of the realm of possibility - We continue to live on. Its still possible although unlikely that there is a supreme being, or even if there is not there is very very much we don't know about our universe, that it would be completely ignorant not to leave the door open for any possibility(except religion). We are just scratching the surface of our understanding of our universe, the possibility of parallel universes, other dimensions etc. You get the point.
Since we can be 100% sure that god doesnt exist in a chrisitan sense, but only 80% sure that he doenst exist at all, we have no choice but to be agnostic. We hope that this isn't the end even though all we know now points in that direction.
I read a book awhile back by TL Galin called "I'm dead, the hell you say, so now what" which the authors take on death is that we chose the life we live it before we live it, and based on how difficult of life we pick is how much our soul grows during that life. Interesting concept and certainly possible, and just as valid as anything else ever written.
So there you have it, absolute undeniable facts as always :)