For me, the main issue of being a believer or an atheist is the fact that we can't even agree on what God actually is. Is it a bearded dude in the sky, is it the universe, is it an entity out of space and time, is it the friends we made along the way ?

That's why I'm agnostic, you can't be certain whether a God exists or not if you can't define it. And in the end, it probably doesn't even matter anyway, why would something like that even consider your existence.