I know you believe strongly in your faith so you might not see my point (and I'm not trying to conflict you), but there is a difference in "knowing" and "faith." You don't "know" that there is a heaven. You faith allows you to believe there is a heaven. And I find nothing at all wrong with that. It's great to have something to believe in. A belief of an afterlife where you could spend a happy eternity. I honeslty hope that that is how it ends and I'd want to be a par of that. However;
Not "knowing for sure" what is to become of us, it can be hard to say. Some people live their life on facts. Not one human being on this Earth knows for a fact that there is a heaven. I strive to do good in my life so that if that time comes and if there is Heaven that will allow me to enter, then I'll be glad to. I follow the 10 Commandments to a tee (aside from the dreaded GD word which I hate myself for using each time i do) and hope that my actions on Earth will be rewarded nicely when I'm not of this Earth. I guess we'll see, huh. Later, QD.