Let's play for a minute. Let's say that I have the ability to choose my beliefs. And let's say that I choose to believe that I am a spiritual being having a physical experience. Now, if I extrapolate that, it could mean that this physical realm is of no real and lasting consequence. It's a game. It's a playground for the physical body and when it's over, it's over. The spirit will continue on in another form elsewhere. (I'm not getting into the idea of karma here. That's a whole other possibility.)
I think sometimes about going back to the jw's. Not seriously, but from this game perspective. If the physical experience I'm having here right now is just that, what does it matter what I do? It might be fun to see if I could actually go back to the jw life and keep a straight face. If I could go back to knocking on people's doors and proclaiming the end of the world. I actually dreamed about this last night. I plugged myself back into the Matrix and found myself a jw. I saw myself preaching and holding a bible and telling people that Armageddon is coming. When I woke up, I felt sick. Go figure.
Now, let's say you choose to believe that there is no spiritual component and that this physical realm is all we have. Seems to me that you could live out the exact same game scenario as above. That again, you could convince yourself that nothing really matters and since this life is all you have, you may as well do whatever you want.
Both of these beliefs don't include the idea of conscience or karma or anything else that would cause us to feel responsible for our actions. There are a million other beliefs that could be born from the original stance. This discussion could go on ad infinitum. Oh wait, it has. Since man came down from the trees. Stupid evolution.