I answered honestly, I do not know. The existence of anything is an inference, based on various assumptions, those assumptions are unprovable, they are assumed this is the core of the scientific method.
I assume the presence of the universe has a rational (not scientific) explanation. I might be wrong but I do assume that. We can readily see that the material processes that constitute the universe cannot be used to explain the presence of the universe, one cannot explain a thing in terms of that thing - try it.
So by extension, there must be some non material agency, we cannot infer much more about that using our material senses for obvious reasons, we cannot scientifically investigate this agency when it is not itself subject to laws of nature.
Therefore it is reasonable to recognize that any deeper knowledge of it will have to be revealed to us in some way, that is to say the explanation for the material realm cannot be found by material science because it is not subject to science. It can only be found by revelation.
For a host of reasons that I won’t go into here, there are good reasons to regard the Biblical cannon (and perhaps some extra canonical works too) as being - to some degree - supernaturally originated.
This is the line of reasoning I use.