Heaven and hell--metaphors or entities? Does it really matter?

Last night a friend asked me if I believe in heaven and hell.

This is an interesting question and a few years ago when I decided to take an alternative to mainstream Islam stance at this I was keenly aware that in doing so I was breaking from generations of dearly held doctrine.

According to mainstream Islam--heaven and hell are entities. At some point in the future there will be a day of judgment when all that we know as matter ceases to exist. When this happens human beings will be given an account of their lives. Those who were good will go to heaven and those who sinned will go to hell. At face value the Quran supports this view and there is a very detailed description of the occurrence of judgment day and its aftermath.

Progressive muslim thinkers however believe that this description could also be a metaphor for heaven and hell as being metaphors for our experiences on earth. Some say that heaven and hell are not entities. Others say that the Quran can be interpreted as describing heaven and hell as both metaphors and as entities.

My Quran discussion facilitator takes that latter view. When I asked him what is true he responded by asking me what I think*. I responded with saying that I believe that heaven and hell are metaphors for my experience in this life. I am not denying that they may exist as entities, they very well might. All I am saying that the explanations given to me of their existence as entities do not appeal to me or strike me as particularly well-grounded. I like to say that I am agnostic their existence as entities. This has led me to a very long and intense discussion with a mainstream Christain, who felt that it was his duty to return me to the crucial and true fundamental of faith i.e. believing in the existance of heaven and hell as entities**.

But frankly if I am agnostic about the existence of heaven and hell as entities, why does it matter? My morality is not based on a fear of punishment in the afterlife. Instead it is based on the obvious consequences I face now. If I engage in generally unadvised acts that act as obstacles in my path (the general progressive interpretation of sin) then I will get negative consequences. As a sentient being with my best interests at heart, I will correct. These consequences can be anything from painful emotions such as lack of peace, anxiety, fear to various forms of punishment by human beings.

At best this makes me more cognizant of the impact of my actions than a believer in punishment in the afterlife. At worse, I am just as likely to be deterred from gross sins as him or her. So if the primary intent of the heaven and hell view is to deter immoral behavior, the agnostic viewpoint does the same.

So what do you think? Is belief in an afterlife central to religiousity and morality?

*a practice among the best Progressive discussion facilitators to prevent group think and encourage individual thinking. One I highly agree with.
**interesting how the other disagreements he has with Muslim doctrine were forgotten at this point :)