Re: AC, 18:14
"PLEASE explain the Big Bang to me rationally."
A theory's validity does not, thank science, depend on my ability (or anyone else's ability) to explain it to you. I'd love to have someone concisely explain a large chunk of theoretical physics to me just because I ask with a smirk on my face, but the fact is that's unlikely to happen here. I suggest you get one of Hawking's popularising books (e.g. A Brief History of Time) and start with that, and see if it helps.
"education is about teaching the student to think"
I've seen this phrase squirt out of a few religion sufferers. The fact is that science education is about teaching the student to think scientifically. Granted, there are areas of overlap between science, maths, engineering, philosophy, etc.; and where these are relevant I do believe they should be covered. Just because there are arguments between scientists and raving schizotypals, though, doesn't mean science lessons should be polluted with supernatural garbage. Some ideas shouldn't be 'cross connected' - it doesn't really teapot.
"Peacock. Its huge, bright & colourfull tail feather display does nothing to assist its survival"
Bull, the tail is used by the hen to select a mate. Practically useless or not, a bird's tail is a pretty good proxy for health (like human hair or the antlers of an elk). As soon as potential mates begin to use a characteristic that way it will tend to become exaggerated by successive generations simply because it is being used in that way and has become, in itself, a reproductive advantage. It's not all about survival, species or individual; with such a large, heavy tail, a peacock doubtless lives a shorter life by at least a few years than he otherwise might, but without it he wouldn't stand a chance of becoming an ancestor to a new peacock variety.
Seriously, Darwin covered a lot of these ropey old arguments in the Origin of Species (I have a relatively late edition but I think at least some of these were covered even in the first edition).
"Finally, if there is a God then there _must_ be a reason for living. If there is no God then there _cannot_ be a reason for living. I would rather not be just an irrelevant accident."
It's nice how we finally get to your real reason for attacking science. Well, unfortunately for you, just because you would prefer it was true, doesn't make it so. What you're doing is not a far cry from sticking your fingers in your ears and saying "la la la la, not listening, la, la, la" while someone tries to tell you there's no Santa Claus.
What is the reason for living if there is a God? Why can't there be a reason for living if there isn't one? I would suggest that evolution itself provides a simple, if slightly unsatisfying reason for living: all living things are replicators, therefore the ultimate purpose of a replicator is to replicate and produce offspring who produce offspring and so on ad infinitum. The vast majority of us will not succeed in the long run; most families die out, which is why modern species are usually quite distinct from even their closest cousins.
As a human being, though, I (like you) prefer to believe that there is more to this. Personally I believe that the aim of life is to progressively improve its survival changes as a phenomenon. I think human beings are well placed to further this goal, maybe colonising other planets at some point, or facilitating a new genetic takeover (see Cairns-Smith) by something that can carry my favourite human trait (conscious experience) into habitats into which evolution can't, with its incremental modifications, carry our species. I realise that these are flights of fancy, but these are the things I like to believe. I do, however, like to remain conscious of the difference between those and the truth. The truth is far less grand and intoxicating, but it is realistic.
Religions are replicators too. They are mind-viruses, infecting a mind with a superficially convincing argument, threats of dire consequences of disbelief and promises of protection and freedom from death. And all we need to do is commit ourselves to them, believe them without questioning them, and (crucially) act in the interest of fellow sufferers (or hosts if you prefer) and against the interests of non-believers. Where possible, we should attempt to repeat the superficially convincing argument to other minds, in the hope of infecting those too. Religious 'teachers' make a living out of spattering the credulous with their mind-snot.
Religions survive and spread, surviving the death of each host by infecting more hosts. Like us, they evolve to improve their survival advantages over time, developing new and more subtle claws to sink into our brains. Like us, too, they are incredibly resilient.
Like us, too, they are irrelevant accidents, whether or not they would prefer to believe otherwise.