....Many of the same things could be said about the concept of the "Big Bang".
e.g., What existed before the 'Big Bang"?
What [or who] caused the "Big Bang?"
And "what" banged?

I found it humorous that a well-known, award-winning Cosmologist who appeared on David Letterman's show a while back, stumbled at similar questions asked him.

The sample of questions above are valid questions because science is not a dictatorship nor an intellectual tyranny.
[Even my use of the pronoun "who" is valid, and not science heresy, because science does not always seek to answer things in isolation. Scientists do at times reach out to the ethical, philosophical and theological communities to put their ideas and hypotheses into perspective or linkage, or to expand their context.

And many Cosmologists are now saying that the universe, or some physical reality that we consider as the substance of the universe, was and is EVERLASTING [ongoing, eternal...whatever
adjective suits the case].

And, funny!...The word "everlasting" is applied by many thiests [Hindus, Muslims, Hebrews, etc]
to God, and by Christians to Jesus Christ.