Richard Dawkins in The God Delusion places himself at 6 out of 7 on a spectrum of certainty that a god exists. That is, on a scale of 1-7 (why 7 I’m not sure), 1 being absolute certainty that there IS a god and 7 being absolute certainty that there ISN’T a god one of the most recognizable atheists in the world pegs himself at 6.
I don’t personally know many atheists who will say that they’re absolutely certain that there are no supernatural beings “out there.” I’m not 100% sure there are no supernatural beings (gods) or realms that we haven’t discovered. All that we know of our universe is natural. I don’t think that there are supernatural realms or entities here, there, or anywhere. But a very high level of doubt and disbelief is as far as I think I can justifiably go.
After all, these beings may be hiding inside cosmic teapots which we have yet to detect.
It depends too on the particular god(s) and how the term is used. I’m very confident that the gods I’m familiar with are human creations. The Abrahamic, Hindu, Norse, Greek, Roman, Aztec, Egyptian, so on, I seriously don’t think any of them exist outside of human culture and our imaginations.
But sometimes a god can be defined or substituted into existence, right? If someone defines “God” as a feeling they have, or as nature then yeah, these things exist, I’m not however prepared to call these things God(s).
Also it turns out that many gods are shape shifters. In the course of one conversation a god can start out as something very vague and misty then be unmasked as a much more specific thing with a more defined personality and agenda. Sometimes a god can be unmasked again and again, with no guarantee that its true nature will ever be known, if there’s a “true” nature at all.
Gods can be quite slippery characters. I highly doubt that they are out there, but I can’t say that with absolute certainty. And that will have to be good enough for me for now.