"least the closest to the truth" If you accept science this is what it means. It's the closest truth humankind has come up with. The problem is that science is constantly changing and evolving because sometimes we can't agree and sometimes we do until some bastard comes and changes the truth.

Right now science agree upon that bible with high probability is a fairy tale. "Gods" that in some form we can not yet comprehend they may exist, but we have not yet seen any evidence at all. And you can't really prove the none existence, so we stand still. So one could argue that its best to asume that there is no gods untill further prof.