So, I'm agnostic. This is an honest question and not some sort of "gotcha!". Why the big bang requires a big banger, but god requires no creator? God is eternal, but how or why? Maybe the universe is eternal and it goes from big bang to big crunch eternally.
Discussion
If I presume what you mean by the Big Bang is the typical scientific definition, then the Big Bang is creation of nothing to something. Non-material, non-existence to material existence. (And no need to argue down the rabbit holes of string theory or multi-dimensional universe theories - that’s just adding pointless layers of recursion on top of the primary point here.)
God is not defined in material terms, so there need not be anything preceeding God. It is from God which all things, whether immaterial, material, or spiritual come from. In Christian parlance: “In the beginning, God…”
Hope that helps frame for you my original argument. 🤙
Oh, and to address your “Big Bang to Big Crunch ad infinitum” idea: that would require a mathematically impossible level of order and design (based on even the most generous age of the universe of -14.6B yrs; and it could be as little as several thousand years depending on your level of interpretation of the Bible) to BOTH events, infinitely, which essentially requires a God untethered to any universe to keep such a cycle from collapsing into full random nothingness.