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

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.

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

Why do liberals and Democrats think it’s “ironic” for Donald Trump to say “We have to get back to law and order”?

THE BIBLE IS THE PROBLEM!

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

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?

DC-area pediatrician on CDC urging summer camp operators to screen for measles immunity - WTOP

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

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

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

Why does my cat get anxious during loud noises like thunderstorms or firework displays? Is this a common behavior for cats, and is there a way to help them cope with it?

A belief in a god is not the problem.

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

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

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