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

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

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 .

What Happens to Your Body When You Eat Watermelon Regularly - Verywell Health

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.

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

Is it possible for creatures with intelligence more advanced than humans to evolve naturally in the universe?

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?

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

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

I told my 13-year-old daughter that she should never start a fight, but has my permission to end it. She got suspended for ending a fight that some other girl picked with her by hitting her then retreating. How do I handle the school’s response?

A belief in a god is not the problem.

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.

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

To a flat Earther, what's wrong with the idea that gravity is simply a force inherent to space which operates only in one dimension? Why do they go further and try to deny gravity rather than just saying it's different than physicists claim?

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