That atheism is not rationally justified

[Chas]

False dichotomy.

3) It could be no other way.
4) It could have been some other way, but it isn't.

But the real point is that there is no apparent fine tuning at all. The entire concept assumes that we couldn't be her if it were different.

So what? Then we wouldn't be here.

Those are not credible options so the dichotomy remains true.

Not credible to you. You are not the arbiter of credibility.

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More philosophical drivel.

I'll defend the position, just for the heck of it. It's not entirely drivel: if some of the quark masses were a bit higher, no stable atoms would form and everything would be a kind of uniform radiation bath with hydrogen or neutrons in it, and nothing beyond that. It would not be a universe with enough structure for a mind to emerge, or Darwinian evolution to take place.

Yeah, but so what? There is no reason to suppose that any of that had to happen.

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...reason is unable to settle things when it comes to the existence of God, can we then rely on hope and happiness to decide on the matter?

Then you followed incorrect reasoning. The existence of a Supreme Being has already been adequately demonstrated, first by Aritotle then by Aquinas, modern hubris not withstanding.

No it hasn't. Reliance on ancient philosophers whose arguments have been shown to be flawed is the refuge of the delusional.