When I left my childhood beliefs behind because they no longer made any sense to me, I was told by my Christian friends that my problem was that I was thinking too much. I think there may be some truth in that. If you seriously think of what you've been told to believe with an open mind, the cognitive dissonance becomes overwhelming and it's impossible or close to impossible to maintain such beliefs. If you seriously think about the concept of an afterlife, it gets pretty difficult to accept it, unless you are able to toss all of your doubts away and keep on pretending that heaven exists.
How in the world can our we exist after our meat bodies and brains die? Our brains control everything that we do, regardless if one believes we have free will or not, it's all about the neurons and neurotransmitters, and how those chemicals are transmitted between neurons via axions and dendrites. It's a bit difficult to understand and we certainly don't have all the answers, but it's not magic. If you want to make it simple, we can just say that we stardust. When we die, what makes up our bodies goes back to the basic elements. Isn't that awesome enough?
But, back to the concept of the Christian heaven. I've known many dog loving Christians who have now included the rainbow bridge in there beliefs. After all, how can we be happy in a place without our beloved dogs and cats. I wouldn't be happy without a dog companion at my side. So, how do we solve this problem? We invent the rainbow bridge, a bridge where our little pets can cross over into the afterlife with us. Okay. That's a sweet fairytale if you don't give it too much thought, but I don't understand how anyone can believe in it literally. At the same time, how can anyone think that our meat bodies and all those cool neurotransmitters somehow reinvent themselves into something else? It's all an imaginative creation, a denial of death, a wish to be able to reunite with our loved ones and in modern times that included our pets.
So, no matter how we define heaven, the only heaven is the one that we create here on earth, assuming that our lives are satisfying enough to be able to do that. Obviously, there is much suffering in the world, so those of us who feel as if we have created our personal heaven on earth are likely to be in the minority, and are fortunate to have been the receivers of positive genetic and environmental influences. To be able to be happy while also being able to detach oneself from the horrors of the world is sort of like living a heavenly existence. But sadly, that heaven will fall apart one day. It may be due to the loss of health or the loss of one's mate, but as the saying goes,"all good things must come to an end" and that goes for a happy existence as well. For, I'm convinced that this life is the only one we have so we should at least try to make the best of it, assuming we have what it takes to do that. Not everyone has been blessed in that department, not due to some supernatural forces, but due to what genetics and influences have given them.
So, my advice is to be a good person to the best of your ability and stop pretending that an afterlife is going to be the perfect place. Just do the best you can to enjoy this life. Sadly, as I've already said, not everyone will be able to do that, as we are all victims or benefactors of what life has given us.