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

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

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

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

Can the right person make a narc want to change their ways? Is love that powerful? Has anyone seen this or experience it?

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

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

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.

What is the belief about the existence of past lives and memories? Do we have knowledge of our past lives at birth or does it come back to us gradually?

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

A belief in a god is not the problem.

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

I Thought My Husband Had a Good Reason to Avoid Sex. Then I Saw Something I Wish I Hadn’t. - Slate Magazine

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

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

Why do some people hesitate to say 'I love you' even after their partners have said it first? How can one interpret this behavior from their loved ones?

THE BIBLE IS THE PROBLEM!