Why does it matter so much to atheists that God doesn't exist?

These are man made rules - made thousands of years ago for the use of the humans who lived thousands of years ago.

Those rules that you are trying to reinstate are rules made by men who didn't know anything about the earth, nor anything about all of the other inhabitants of it. How can you not see that?

And then use and ENJOY these fantastic scientific advancements every single day of your life?

TSA issues warning as they ban certain card at airport security that's owned by millions - UNILAD

A belief in a god is not the problem.

And how do you deny hundreds of years of advancement in all fields of science?

IT does not matter, mainly because it does not exist.

Why do some of those who believe in a god refuse to consider the possibility they could be wrong?

The people of the modern world have evolved past all of that nonsense.

THE BIBLE IS THE PROBLEM!

My problem is that people who try to shove their rules down everyone's throats - including by physical force - DO EXIST .

Nuclear rocket engine for Moon and Mars - European Space Agency

Because these are not any gods rules we are talking about.

I am speaking to the US Bible thumpers here, of course ~ many of whom are flat-earthers who deny evolution and see scientists as evil people who are constantly trying, and succeeding, in disproving their beliefs one by one.

Notice that I said their rules, not any gods rules.

Doctors warn just one glass of this drink a day could increase risk of being diagnosed with cancer - UNILAD

I do not personally care if you believe in a god or not.