Posted: Apr 30, 2019 7:42 am
We don't have to think anything ever did.
nor do I think that the universe's origins can be explained by going back infinitely through a series of events, ie a big bang preceded by another, and another.
Nobody thinks that. By definition, something that has existed endlessly into the past never came into existence, so didn't have an origin. If there was no origin, no coming into existence, then such a transition from not-existing to existing doesn't need to be caused or explained, because the event did not happen. We don't have to explain how events that never happened were caused.