You don't beleive and you do so for the the same exact reason. There is no proof that he doesn't exist yet you don't beleive, you're not on the fence about it.. you straight up deny the existence of a creator period bibilical or not.
I do try to see if a God actually exists.. in fact the religion i subscribe, if you want to call it that, to actually encourages that you go out and do this.
I've also had experiences that have let me know God exists, which have been my largest indicators so far... but these are my personal experiences so I can't speak for everyone.