The reason for the captilization of the word "God" is to give respect to him, "god" is a more gernal term, usauly refering to statan in the bible.
That's why it's VERY important to captilize it, other wise your as good as saying, God and satan, are the same!!!
That's why we always use the non-capalized "version", like "gods" instead of "God", but that's not as important as the fact that, THERE REALLY IS ONLY ONE GOD! The reason is because, for one, look in the bible, how on earth (or any where else for that matter) could God have fit all those "secret meanings" in everything?!?!?! How could any man have done that? It would take him LONGER than a life time.
Anyway, that's my reason for beleiving that for one, the word "God" should be capalized, and why there is only one God, of course, there are MANY more reasons for why there is only one God. Just check out ONE of these blogs, you will find lots of the "secret meanings" I was talking about earlier:
goldenbible.wordpress.com
gospelblog.net
jesusworshipper.wordpress.com