God wasn't created, he always was.
That is unsupported speculation based entirely upon religious faith. As such, it has no rational basis as a substantiated premise. Your next sentence indicates that you seem to be aware of that you are unable to satisfy the burden of prrof requirement for initiating that claim.
I wouldn't spend much time puzzling on that as it isn't something we could ever understand. To be more precise, we think in terms of 'time' and duration, but such things are properties of our universe that appeared after it's origin. If you ascribe to the "big bang", then time arose after it did, and mentioning events before the big bang is problematic as one will find it difficult to describe 'before' when there is no 'time'.
The reference is to the time-space continium which includes such concepts as "duration", "before" and "after", yes. This neglects the theorectical premises of having more than four "dimensions", (as in superstring and other theories). Mathematically, some 4-D processes 'work' if these 'extra' dimensions are figured-in to the equations. With some 11-dimensional theories, "time" doesn't have the same attributes as in 4-D space-time, (point-dimensional aspects apply instead). Within such theories, neither an 'eternal' nor 'creator god' are required to be unnecessarily hypothesized in order to account for sub-quark particles "appearing" And "disappearing, (from and to these other mathematically-posited dimensions). Yes, these are scientific theories however, they have at least some extensive mathematical basis whereas just saying 'godditit' has none whatsoever.
If you ascribe to the "big bang", then time arose after it did, and mentioning events before the big bang is problematic as one will find it difficult to describe 'before' when there is no 'time'.
There are other theories extant than just "big bang", (even insofar as variations on BB, such as steady-state & cyclic 'bang' theories for instance).
So far there are no theories put forth by scientists that could qualify any of the questions that would arise about the creation of the universe without bringing up more questions than the answers they provide. None of the existing theories (that I am aware of anyways) work within an empty set.
The empty set objection presents an inaccurate premise in that it is inherently applied to 4-D space-time and changes aspect when applied to additional dimensions, (11-D for instance). This can get extremely complex in aruing mathematical proofs however, interested persons can look up such things as 'more than 4 dimensions' and 'emergent physics', etc..
Unless you can demonstrate a way to separate nothing into a negative and positive part of equal (but opposite) values, with substantial properties associated with each of them and the capability that they do not readily reform and neutralize themselves, then I feel any theories could never qualify as "everything from nothing".
Well, that would actually be 'nothing from anything that you can see', (such as non4-D dimensions and precurser emergent phenomenon stemming from them, (e.g., the "tunnel diode effect" for one example).