Okay, as a hypothetical way to test once and for all if there is an afterlife/soul/God/whathaveyou, I propose the following: If there were a way to "kill" you, at your request, to where you had absolutely 0 brain function or body function, then bring you back to life one would find you reporting one of the following two results:
1) You didn't see God and there is no afterlife. There is no heaven. You just went quietly to sleep and woke up again without anything in between.
2) You saw God. Jesus wins!
Would the test convince you one way or the other? If you saw God, you would certainly be convinced He existed. If you didn't would even that be enough to convince you it's all bullshit?
Clearly, once you terminate the organism we know and understand to be the human body, it does not "live again" so there is no "afterlife" as it pertains to the physical body. However, genetic engineering makes it theoretically possible to recreate the human organism precisely as it existed before death. While this is a science in its infancy, it is indeed a science developed by the imagination of man himself. If man could conceive such a concept, it's not out of the question to believe a supreme being could do so.
We also have some evidence that other dimensions of conscious awareness may exist. Ghosts, poltergeists, UFO's... things we can't really explain with science at this time, nor can we claim to fully understand or comprehend. For centuries, mankind has referred to a spiritual entity residing inside our body, we call it a "soul" but again, science can't explain it or even attempt to. How can we determine what happens to this entity at death of the physical body? Well, first we have to find rational belief that a soul actually exists. Can this be done with science? Perhaps.
From an archeological aspect, the oldest civilization of humans we have ever found, Mungo Man, discovered in Australia in 1974, shows evidence of ritual burial using ceremonial ocher. So we have direct evidence that humans did indeed believe in an 'afterlife' and 'soul' from as far back as we can go. To date, 95% of the humans on Earth, believe in some kind of 'afterlife' or 'soul' and this is important from a science standpoint, because we have observed that animals always retain behavioral characteristics for a reason. There are virtually no instances of a species retaining a behavior without fundamental purpose and reason. In spite of a complete lack of physical evidence to support the belief, it has been persistent in humans for all of recorded human history. If the soul isn't real, there certainly seems to be a fundamental need in man to believe it is real.
What is really intriguing is the fact that you, an admitted Atheist, have posted yet another thread, to 'argue' against the possibility. Now, most of us don't actually believe there is a bunny rabbit who hides colored eggs on Easter Sunday, but very few of us have devoted as much of our free time on a message board, attempting to refute what we claim to not believe in. Generally speaking, if we honestly disbelieve something, we don't bother wasting any time refuting it. If others believe it, that's their problem, not ours, we know better. But for some reason, anti-God people spend an enormous amount of time and energy attempting to refute what they claim not to believe in. Again, the science of Psychology tells us there is a fundamental reason for this behavior. In your mind, you realize your disbelief in an afterlife is not a natural human inclination. Whenever we experience something unnatural, we seek to involve others in that same experience as a way to validate what we want to believe. If you saw a UFO, your first inclination would be to find someone else to witness it too, because you need the validation for what is an absurd abnormality. Denying God, souls and afterlife, is not a natural human condition, and you realize that. This is why you seek to gain 'support' of your viewpoint with others. Here on the JPP forum, you know there are others who disbelieve as you do, so these threads are a plea to them, to help you validate the absurdity of what you believe.
