The word "god" is always a noun as far as I can tell, but when it is used with either the definite or indefinite article or with a possessive, it is quite proper to use it without capitalization. When it is used as a name, though, it becomes a proper noun and should be capitalized as such. For example:<quoted text>
No, the label of "god" is an adjective, not a proper noun. Get over yourself. Your god is no more privileged than the other thousands of gods, because your god has the same amount of evidence as those others.
No god worthy of worship would require a man to sacrifice his son.
I killed them because God told me to.