John Hick asserts that “we are accordingly faced with the choice of accepting God or accepting the existence of the physical universe itself as a given unintelligible and mysterious brute fact”. (p. 83)
The statement summarizes the situation succinctly. Either the universe was created by God or it was not. Theists have discovered that the divine explanation is far less improbable than the natural explanation. We know that the universe didn't exist at some point in the past. What caused the beginning of the universe? We know it could not have come from nothing because ex nihilo, nihil fit (from nothing, nothing comes). A sophisticated but ultimately futile attempt to overcome this maxim is the phenomenon of virtual particles appearing out of the vacuum of space, otherwise known as fluctuations of vacuum energy which is supposed to be a contravention of nothing coming from nothing. However, the vacuum isn’t exactly nothing. If there is energy present, then vacuum is a term that is only a close approximation of actual nothingness. Thus, vacuum fluctuation isn’t really creation from nothing but, is creation from something. The question then becomes why does vacuum energy exist? Where did it come from?
Since it has been established that the universe could not have come from nothing, there was something before that caused the universe. What is the source of that prior cause? If a natural explanation is offered (such as cosmological inflation), then this chain of explanations invites infinte regress, which is an impossibility. We know that actual infinites are impossible, even if potential infinites are possible (such as in mathematics). Given that natural explanations are unsatisfactory, there had to be a supernatural, uncaused cause behind the creation of the universe. There has to be brute explanation, an explanation to which there is no more explanation, the ultimate explanation. Since this reasoning can only lead to God, it makes Hick's former explanation much less fanciful and ad hoc than attempts to manufacture the latter.