Let me help your understanding. Before the Big Bang, there was nothing,.....No Thing. No time, no space, no matter. Nothing. Yet here we are. If natural forces existed, and we have zero (0) evidence of that then why would unknown forces “decide” to create anything? A decision was made to convert ‘nothing’ to something which we know as the universe. Forces don’t ‘decide’. Forces are not a mind. Yet here we are. Something separate and distinct from this time, space, matter, energy continuum made a decision to create a universe from nothing. So my question to you is,....Why is there something at all, rather than nothing?
Having all the mass of the universe collapsed to a point would be the ultimate black hole; nothing would ever "bang" its way out of that. Likewise for a supposedly omniscient and omnipotent God to suddenly determine that it would be a cool thing to do to create a universe (7000 or 17B years ago, it doesn't matter) while the idea had never occurred to him previously in the infinite expanse of time prior to that, is basically nonsensical.
The creation stories we see in the Bible and other antique literature almost certainly refer to the creation of our own living world and local environment and not to the entire universe. The universe, like God, is probably eternal.
That link I provided indicates that the list of physicists and other scientists who do not buy into "big bang" includes some of the people who run Las Alamos and other top physics labs.