Atheism vs. God's Existence

[TheRocketSurgeon]

I am curious what some compelling reasons are for becoming an atheist. What are some reasons that have been the deciding factor?

It seems to me, judging by the large number of versions of "there's no evidence" one-liners, that many people who identify themselves as an atheist espouse some sort of positivist argument:

Positivism is a philosophical theory stating that positive knowledge is based on natural phenomena and their properties and relations. Thus, information derived from sensory experience, interpreted through reason and logic, forms the exclusive source of all authoritative knowledge.[1] Positivism holds that valid knowledge (certitude or truth) is found only in this derived knowledge.[2]

Verified data (positive facts) received from the senses are known as empirical evidence; thus positivism is based on empiricism. https://en.wikipedia.org/wiki/Positivism

However, there are a bunch of problems with this philosophy so most atheists' arguments aren't very sophisticated. BTW, the same thing happens for theists--many do not have sophisticated arguments for their belief--relying on experiences and trust in the contents of their holy book(s). 

The question of the existence of God cannot be commented on by science--not at all. These are metaphysical questions and reasons and arguments for and against the proposition are necessarily metaphysical in nature.

Yes, we would like empirical evidence before we accept your claims about how your gods throw lightning (which seems apparent to us to be caused by differential charges between the clouds and/or the earth, resulting in a sudden exchange of electrons) and make thunder (which seems apparent to us to be caused by the rapid expansion of the air around the electron bolt), which you say we should worship according to ancient writings. I'm sorry, but we have better explanations than the magical acts of the gods, now, and it's just not a valid candidate for my belief.

Oh, were those the right gods, or no? To which magical fairy-story were you referring, then?

The one where lots of people really really really believe it, and claim that they feel in their hearts that it's true, and you think that constitutes evidence for your magical claims?

Yeah well I think Hinduism is silly, too. Definitely not a candidate for belief.

Still not the right one? Hmmm, let me think... perhaps it's the one with the "Authenticity" of the "Revealed Texts" handed down directly from God through His Prophets.

Well, I read the Qur'an, and I didn't find it to be remotely convincing as a divinely-inspired work. Definitely not a candidate for belief.

Is it the story with the divine beings of light, wielding a flaming laser-sword and guarding a magical garden containing magical snakes and magical trees of knowledge, where they claim mankind was made out of clay and women out of ribs, when the world was magically created 6000 years ago?

Because I think that one's as silly as the rest of them. Definitely not a candidate for belief.

Please, then, tell me which one you mean, and why I should reject all the others but accept that one, lest I be labeled a "Positivist" and sneered at for wanting some verifiable evidence of your magical claims before thinking they're real.

Oh, I know which one it is -- it's that cult where they say you have to join the cult and really really really believe, and THEN you'll understand!!

Nah. Don't like cults.