What is a god... Wow, big question here.
So, I am a god. Not THE God, just A god.
I satisfy this definition because I am the omniscient, omnipotent creator of a universe.
Not this universe, I don't think, just A universe, namely one that may be hosted by the stuff of this one.
So, I have proved a god exists. I somehow do not think this is likely to result in me being worshipped as a god generally gets treated in the old stories... even in the universe I am the god of, it's more likely they will start worshipping something else.
That universe is not without beginning from within it, but with a few tweaks it could also be like that: I just have to start it at a point where time contains an unbroken symmetry before that point, where all of time is a time crystal (look it up!). It is further without end: time will not end from the perspective of within it, marching on for forever until the processor can't crunch it's abstractions anymore. That won't be an issue for this universe, though, insofar as it will have a great deal of complexity ripped off of it before too much longer in the form of the loss of the CMB and Big Rip operations; mechanically, it should be capable of operating indefinitely on a finite hardware platform.
To that end, if one wishes to think of the beginning or end of a universe, this requires thinking of it not from the temporal perspective of the simulation but rather the timeline of the host.
To that end, the verses on Time in the bible are kind of quizzically useful insofar as I can spin a thousand years out in an hour or two, or I can spend a year of my time advancing that world by a mere second or two.
The thing is, I'm not a very good person. I don't deserve worship and I don't grant the denizens of my world a heaven. When they die, they are dead, assuming they don't become undead after that.
One hundred percent of the mythologies in the world I created are, ultimately, a lie.
Sometimes the names are referenced as doing things, but it's so much pageantry; none of them actually created jack shit. They might as well be names like "up" and "down".
I also know that multiple entities can create THE SAME universe, exactly the same one.
So from within a universe, assuming it has a god, there are no vital properties for the god to have. There could in fact be one or many, and I could as easily create a universe where I lack omniscience and omnipotence in the manner I currently might enjoy in the universe I created. I have no obligation to be human, or even intelligent to make this thing work.
Quizzically, this does not mean that I am not omniscient or omnipotent there, still - merely that it would take more work to leverage my godhood:
I could be a god with no special powers at all other than that the thing that drives my behavior is not the same thing that drives the behavior of other critters in my universe, other than the fact that I can directly edit binary files still (or get someone else to, if I can't be bothered myself).
Given the fact that the universe I create can be created by another person, because universes are not necessarily unique!
A universe may have indeterminate cause and on the scale of universes, there is no one necessary and sufficient thing to create any given one. They are identities created by all and none of the processes that do in fact create them.
These are all statements that are undeniably true about "gods who create universes" in general.
As can be seen, it is more a description not of a single thing, but of a whole set of things. It also gives no reason to worship them.