Modern physics views nothingness as being unstable. No space and no time, no dimensions, no matter, no energy (or no forms of energy other than potential energy) with the space that we currently see, the visible universe, being infinitely small, essentially zero, that’s how nothingness is seen.
Of course, people will say that there were laws before that (although there can’t be a before if there was no time).
Anyway, I don’t know the answer. You will have to consult the mathematics of the big bang if you want to know more.
I myself have played a little bit with the mathematics of the Robertson-Walker metric, and I have more or less gotten the first few minutes in Gamow’s scheme, but before the first few minutes, like the infinitesimal times modern cosmology discusses I know only as a story, not as math.
I don’t know that people will ever really get time zero though, so even if they got to something like 10^-30 seconds or whatever, God might still be as ‘safe’ as if they couldn’t get back to last month.
At one point, Steven Hawking wanted to have the early universe be a regular singular point, but he ultimately abandoned that idea. I don’t know whether or not he still clings to imaginary time.
There are other ideas for doing without God, but I don’t have any real confidence in them any more than I think that any of the theoreticians grasp the nature of quantum mechanics.
While I occasionally investigate cosmology etc., I still pray, think about the afterlife, and think about heaven and God.
I rather doubt that anybody reading this will ever live in a world where these things are really understood.
In my opinion, you don’t need to worry about any of these things, you really don’t.