[Heartlander]

If nature did not bring anything into existence – who did?

[BMCDA]

Why does it have to be a "who"? I think a "what" would be more appropriate.
And as I said before, nature just is and it is not appropriate to say that nature does this or that. A natural process occurs and there is no intelligent agent influencing it. I don't understand why you insist on that word.
If some atoms bond and form a molecule, who created this molecule? Or an interestellar cloud collapses under its own gravity and forms a sun and planets, who created them?
It simply happens. That's it.