One disordered attempt, none of the arguments are original:
The only reason to be religious or believe in a god is because someone is telling you to or because you want reality to be a certain way. That is to say there is no reason even by common sense standards (you wanting something to be is no reason for saying something is so). All religions are creations by humans, their origins are in ignorance about the natural world, and there are many other mistakes and arbitrary elements as well, just the same as in other human history or politics, or literature, and many other things.
"God" is irrelevant to knowledge, to being a good human. Knowledge is come by its own requirements (what else?), and it's no different to being a good human.
The only way that a "god" cannot be disproven is because you can't prove a negative. That is a formal reason (you could actually theoretically progressively disprove god being at any one point). But you can prove that everything surrounding that element is irrelevant or wrong, or merely human (psychological, sociological reasons: living itself; plain normality), and that every version is equally absurd (though theoretically here and there more reasonable, but this is dangerous stuff, and not really that important), and ultimately the origins of that element are nothing else than the same circumstances as those irrelevant, wrong, or quotidian things, and also that this "god", whatever it's supposed to be, doesn't fit the true nature of things, the same as any fairy-tale, or is too restrictive and parochial to hold onto as a "theory", and the reason for doing so would probably be purely personal and have purely personal effects in life, and is so once again without real reason (see above) and have no relevance to the question of knowledge and explanations or even how one "has to" live. ...