Thief
Rogue Theologian
We can know with certainty the answer to this question because time and space did not exist before the expansion of the universe. Without time, there is no before and therefore no cause and effect. The answer, as counterintuitive as it may seem, is "nothing."
No 'thing' means exactly that.
Something from nothing?
Nay...I don't think so.
You would have to abandon science, logic, all forms of certainty.
Without cause and effect....no thing can be sure.