Luke Poulin said "Ray, have you ever, just once, considered the possibility that there is no after-life? Did you ever meditate on that idea? The idea that, once you die, it truly is over?"
A Christian knows God. We don't simply know "about" Him. We know Him, and because of that we KNOW that there's an afterlife. Let me see if I can help you relate (I don't say that condescendingly). Have you ever, just once, considered that you are not alive? Did you ever mediate on that idea? How would you answer that question? That's the dilemma I have in trying to answer your question.