"Does God exist?" is the wrong question.
If you answer yes, the world is one way.
If you answer no, the world is the exact same way.
Verification: care to propose an experiment to tell the difference?
E.g. I can be sure Zeus doesn't exist because he's supposed to live on Olympus, and no satellite can see him. But the monotheistic God has no analogue.
Which means the only difference is how the belief makes you, personally, feel. Even, "I follow the Bible because I believe in God" is a non-sequiteur. The key spiritual truths in these books are equally untestable.
There's a reason they're all about 'faith' and it is because their founders weren't idiots. They knew they were, experimentally speaking, shovelling bullshit that nobody can prove or disprove. So they exploited the guilt-by-association fallacy in reverse.
Both atheism and theism are wrong, in exactly the same way both are wrong in a debate between someone who thinks green dreams sleep furiously and someone who thinks green dreams party sedately.