Life after death. Heaven or hell, or nothing. What's on the other side? What do you believe is there? Does what you believe about what is there or not, actually change the reality? What is real? Where's your evidence that what you believe is real? How do you know what is true? How much of what you believe is based on irrefutable evidence? How much is based on what other people say? How much of what you believe is just stuff you want to believe?
If you see it with your own eyes, is it true? Hear it with your own ears? What if your senses deceive you? How can you know for sure? Maybe somebody else saw it. Is one witness enough to convince you? How many would be enough to prove it? What about the credibility of the witnesses? Do you believe them? Do you trust them? Do others trust them too? Who is right and who is wrong?
Answer all these questions, then tell me if you know everything. You don't know everything, so some things which you don't know are possible, aren't they?
What's on the other side? I don't know because I've never been there but I do know what I believe is there and my faith gives me strength.