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.

THE BIBLE IS THE PROBLEM!

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?

How do I build rapport with anybody?

IT does not matter, mainly because it does not 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.

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

As a NATO/Ukraine supporter, since you're so blown away and angered by Trump putting Zelensky in his place yesterday, why don't you support the Ukraine by joining the Ukrainian army? There's 200,000,000+ of you. Put your money where your mouths are.

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

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

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

When writing a novel, how can a character be developed well, but QUICKLY?

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

A belief in a god is not the problem.

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

What is a good investment portfolio for someone starting in their 20s? 90% VT and 10% BND for a Roth IRA then 100% TDF for a 401k?

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