I came across this picture on Pinterest months ago and for some reason it has just stuck with me. The third photo from the top particularly had an effect on me.
I just don't see how heaven can exist. And I'm not even talking from the perspective of whether or not we have souls, how a being could live forever, etc. I'm talking about the idea of a place where humans are eternally happy. I just don't see it. Such a place could only have been designed with assumption that the world is the problem, not humans. I think a lot of the evidence points in the opposite direction: humans are the problem. Of course phenomena like illness and natural disasters contribute to human suffering but a large part of our suffering comes from issues within ourselves and the innumerable ways that people hurt each other. Basically, for heaven to be heaven, you couldn't be human as we understand the concept.
To be utterly happy in heaven, you couldn't be you. But I don't think that that's how people think about heaven. I think they see themselves as they are (maybe a bit more attractive, smarter, etc) but without anything that makes them sad: "every tear shall be wiped from their eyes," etc.
Even some of the concepts mentioned in heaven (I'm talking strictly from a Christian perspective here) showcase many of the flaws of humanity. For example, people often mention living in mansions (John 14:2) and walking on streets of gold in heaven (Revelation 21:21). Wouldn't these be as vain in heaven as they are on Earth? If we lose our flesh (physical body), why do we even care what we live in or walk on? The fact that people get excited about this stuff shows me that if heaven exists, it won't be too different from what we have here.
And this is leaving out out several other critiques of heaven: the monotony of doing anything forever, the fact that many wonderful people who happened to be born in the wrong religion won't be there while many horrible people who were born into the right one will be, etc.
Confession: I have started attending church again. However, philosophical issues like the one I've discussed above just won't leave me alone.
I hope there isn't an afterlife and, if there is one, people like me can select the 'other' option and can choose to have eternal rest.