My biggest problem with the 'belief system' is that the concept is so extremely narrow. It literally does not allow one to explore anything else and true knowledge comes from exploring the world and all cultures, religions, traditions etc. How can I say 'I know' when I haven't experienced of what I think I know? We wouldn't have had science if we were only to subscribe to only one belief system - no matter what belief system that is. Even when some people call or see themselves as 'atheists', they are essentially subscribing to a belief system.
For example, Mellen Thomas Benedict was told that he had terminal brain cancer and had about a few months to live. He was in his early 30s and was an artist who was barely making ends meet. He had a lot of trouble accepting this truth however his condition was to the point that it wasn't even operable. The tumors had taken all over his brain and the cancer spread even further. He left town to die alone. And then he died. It's worth mentioning at this point that he didn't have any belief system in him; he wasn't even an atheist because in his own word, 'I didn't even care for that'.
After he died and remained dead for an hour and half, he had an amazing experience and after that experience he was told that his time wasn't up yet and that he was to go back to life to finish his mission on earth. He then returned to his body with a complete remission of the disease – and what may be the most inspirational near-death experience story known to date.
I have the youtube link on the Dream thread of this remarkable story if anyone is interested to check it out. In short, however, his experience is a positive one despite not having a belief system and he literally came back from being dead. He was told the reason why he had cancer in the first place was because he brought that upon himself, as his outlook on life was quite a negative one (you can read further in his biography or in his book). He was told, even though he had an extremely rough childhood, he could have redirected all his anger and negativity into something positive. He had the choices and the power within him to do that. So how we live our life in this lifetime is far more crucial than to subscribe to a narrow belief system and live on that. Because the belief system doesn't really set you free if that's all you are doing.