well since Mr Null brought up the subject, I said I'd blog a bit about why I believe in God...... so here's just a handful of reasons, hastily written in the early hours when I should really be in bed...
First of all I should point out that I'm not one of those dogmatic bible bashers who invariably wants to have the final say in what people should believe or how they should live their lives, this is just what I believe and I'll gladly discuss it with any reasonable person of any belief. Another point is that I think there is no completely logical argument of the proof of God, ultimately it's a leap of faith but then so much of our existence is the same. I think it was Descartes who said "I think therefore I am (ie. exist)" meaning that's the one single thing we can really be sure of - which is a self-evident truth I think. So everything else is open to interpretation - some things seem more obvious than others of course.
I know organised religion has been used to control and influence people in a negative way which is something I wouldn't defend. I'm not sure that it says so much about religion per se as it does about human nature in general. Power corrupts and all that. Having said that, I think religious beliefs have caused people (Mother Theresa etc.) to do great and generous things which go against human nature so it does have it's benefits. I don't think you have to have religious beliefs to do good things but I think if you do, the chances are you'll go the extra mile or two (maybe!)
Anyway, one of the main reasons I believe in God is ethics. We all know intuitively that right is better than wrong, good is better than evil, life is better than death etc. but if our existence is completely arbitrary and purely a matter of mathematical probability in a huge random universe, then in the big scheme of things none of those things do really matter despite what our strongest feelings tell us. Why is it better to save lives than to take them if they don't have some special value? If you don't believe in some higher meaningful existence then ultimately it doesn't matter. In that case, your existence in the first place is just a matter of chance, any awareness of feelings are simply a product of physiology and when you die, you'll forget you ever existed in the first place and the whole process of life and death and birth doesn't lead anywhere at all, it just happened by accident. So, I could go out and murder someone tomorrow and it could get me into a lot of trouble which would be annoying, but it wouldn't actually be fundamentally wrong. Of course it would cause suffering and pain to the relatives and family of that person, but what's wrong with suffering? Why do the feelings of those people matter too? Some could argue that self-preservation is why you have those values of right and wrong, good and evil but if there is no important reason for us existing in the first place, then what difference does it make? What's so great about self-preservation? It might feel important to stay alive and keep others alive but that importance would actually be an illusion - maybe it is - in which case it doesn't matter what we think anyway. If however, there is a point to everything and our existence isn't just an inconsequential event in a meaningless universe, then suddenly everything is meaningful again. My life certainly feels meaningful - it might just be an illusion, but personally I doubt it. There are people who claim to have an explanation of ethics without the need for religious belief but I've not heard one that's convincing, and like I said before I don't believe there is a watertight logical argument for any of this, simply because by it's (super)nature it's illogical.
Also, we have consciousness and feelings and personality. Again these could just be an illusion or could have just arisen out of pure fluke. But, I can't believe that a soul-less universe with no conscious being overseeing it could actually create something so intangible, mystical and amazing. It would be like a robot giving birth to a live flesh and blood baby - where did it get the DNA and the plans for the human baby in the first place? So, what I'm saying is that I think the fact that we have personality, feelings etc. reflects the fact that existence/nature/the universe itself also has those attributes - but on a much larger scale, and I think that giant super-intelligent personality is what we call God. It just seems implausible to me that us intelligent, thinking, feeling humans would pop up out of nothingness and find ourselves in a universe that is completely alien and unemotional, like some kind of existential accident that never should have happened.
Another thing which I think confirms that there is an important meaning to life, and therefore a God, is the number of mystical/supernatural experiences that people have. Millions of people have had amazing, inexplicable, life-changing experiences - religious or just plain spooky (and quite a lot of people have probably taken too many drugs or gone a bit crazy but I'm not talking about them). A friend of mine from University who is the most level-headed, rational, non-spiritual person you'll ever meet saw his own grandfather walking up the stairs in his house - five days after he'd been buried. It turns out several of his family members saw the same grandfather at various times. If I didn't know this friend so well I might not take him so seriously, but knowing him the way I do (and how sensible - and cynical he is), something very inexplicable but very real was going on there. Things like this happen to people all the time. Okay it doesn't prove the existence of God but it might suggest that there is more to existence that what we percieve in this world. Science doesn't really have any opinion on the subject because it requires provable empirical evidence, but I think it's extremely likely that many things exist which cannot be scientifically documented and tested in a lab. Some scientists will say that if that can't be done, then it doesn't exist which I think is a big mistake, they should be content so say that science cannot prove it's existence (i'm talking to you Dawkins). Of course science is a discipline which requires strict rules, but to live only by what can be proved in a lab seems rather too conservative to me, considering what other important things you could easily be overlooking. Nowadays we live in a culture of scientific reductionism where just about everything can be explained by some crude mechanistic model of physical laws, and anything which isn't or can't be explained therefore doesn't exist - which is kind of a self-fulfilling prophecy (a bit like CFS - "we don't understand why you're so ill - so therefore you're not ill!"). I don't want to sound like some kind of crank that thinks science is all wrong and we should all believe in fairies. I studied genetics and evolution and biology at University and that all makes perfect plausible sense to me. I just think there's a whole lot more on which science is just not qualified to comment, but which certainly exists judging by human experience over the however many millenia we've existed. Since we learnt so much about science and developed such great technology, we've created a culture which believes that only solid, tangible, provable things exist and everything else is just silly fantasy, but I think that's just a recent secular cultural convention which we've started to take for granted. I've been a Christian for about 15 years and there have been times when I've prayed and prayed for something and my prayers have been answered in a completely surprising and unexpected (and often implausible) way. I'm not going to go into details, and the circumstances weren't completely miraculous but the memory of what happened just seems like that extra bit of proof to me that there is a God that exists and knows us all personally.
Having said all that about science, the cutting edge of physics does seem to veer away from the simplistic, deterministic view of nature and get into some very weird concepts that could be considered philosophy/religion. The whole field of quantum mechanics requires us to exist in multiple dimensions, and for there to be countless parallel universes etc. and that things considered impossible to classical science (eg. the supernatural) are simply a matter of probability when thought of in terms of quantum theory. This seems perfectly plausible to me that if you study nature closely enough eventually you'll find proof for the existence of such things. Here's a good page on the subject.
Something that occurred to me a while ago when having a similar discussion with my brother - him saying how daft and implausible the idea of an afterlife/heaven/other world is, well we only believe in this world because we're here experiencing it. If we were just bodiless spiritual beings drifting in nothingness outside time and space, we probably wouldn't believe in an earth that has a sun and a moon, and seas and land, and animals and people. If you think about it, it does sound kind of weird and implausible but because we're here we take it for granted - and if we refuse to believe in anything else (other existences, heaven, God etc.) then we're just like those bodiless beings in the nothingness who would have been totally mistaken. Of course that could be an argument for believing in absolutely anything and expecting it to exist, but given the infinite variety of different worlds we could imagine, I think it's useful to look at what religion has come up with having thought about the subject for several millenia and narrow it down a bit...