I personally think that we have to find our own heaven; much as how we have to find meaning in our own lives.
If we look at heaven as a place outside of this world, then yes I think it exists; but not as we're told through religion.
I think that the point of existence is to be here, experiencing the world by learning, sharing and growing. Heaven or "the other side", for all intents and purposes, for me anyway, is like going back to the office.
You meet with the boss, let him know how you did, what issues you had, things you need, how things are going ect. You stop by the water cooler, talk to some co workers, maybe help out someone there with a project for a bit and then after a while, you're ready to hit the road again.
When most people speak of heaven, they're usually implying that they want to or expect to see their families again. And the truth is, this may or may not be possible over there as they may have reincarnated already! But given how pervasive and strong the bonds are in soul groups, we'll always see our family again, even if we are apart for a little while.