What are the chances there’s a god out there, somewhere in or beyond the Universe and responsible for it and us?
It is fitting to bring Bertrand Russell's concept of a sun-orbiting china teapot into this deliberation—or the Flying Spaghetti Monster—and let’s try judging similarly. Think up something new, whatever you like that is implausible and untestable, much like the teapot or spaghetti monster, and then consider the chances of its actually existing anyway. The answer is ZERO—seeing that such a proposal is a fabrication by definition, and is necessarily untestable anyhow.
Now, invent a deity of your own. It is obviously fictitious because you are creating it—so it joins the millions of other gods envisaged by superstitious people, every one of the gods as unprovable as the others.
Yet this is what the Bronze Age goat-herders in the desert margins of the Near East did. They dreamt up a personal god as a means of justifying, to their simple satisfaction, what little they knew of the Universe and Planet Earth. For them Goddidit explained everything. À fortiori, no other human-invented gods have existed either, seeing that most people who hold to a religion think that all religions except their own are false; hence the paradox and its refutation.
Probing more deeply, any search for a timeless pre-existing creator figure is also doomed because, by the principle of infinite regression, this would lead to the need for a creator of the creator of the creator, ad infinitum.
Therefore, if instead anyone chooses to contend that some creator god has always existed, as syllogising deists want to assert, then the obvious alternative can equally be claimed: namely, that the Universe has always existed … and that it is being ever more accurately explained using only the laws of physics that are supported by ever-improving, wide-ranging empirical evidence.
In short, the Universe—or any potential Multiverse or Infiniverse—
always has been,
always will be
as set out in Testament One of the volume “A New Bible in Three Testaments”.
Let’s then be content in knowing how lucky we are to be here, philosophising about the Universe and playing our tiny part in it during the fortunate few years of our lives on this wonderful planet.