Their is no conflict between believers and atheists. Why not? Because there aren't any atheists. There are only people who claim they are atheists.
Why aren't there any atheists? Because nobody believes that God doesn't exist. Any people who say so, really know that God might exist somewhere they haven't examined. This makes them to not be atheists, because of the definition of atheism.
You struggle with the definitions. All atheists reject the claim that there is a God.
Some atheists have strong convictions that there is no God (myself included), some say they don't know whether there is God or not.
But all atheists reject the claim that there is God. Period. As such they don't have to prove anything. They are not making any claims. They are rejecting Theist claims.
Personally, I think there is maybe 1% chance that there is something that triggered the Big Bang, and 99% chance that it all has started by itself.
The 5000+ Gods described in ancient books do not exist for sure, IMHO.