By faith we understand that the universe was formed at God’s command, so that what is seen was not made out of what was visible. “that what is seen was not made out of what was visible,” in other words, ex nihilo, from nothing.
I believe that God is the Creator of all, but I do not count “not visible” as the equivalent of “nothing”.
I try to be very careful not to “add to” or “take away” from God’s word. I don’t pretend to know all and I find many things in the Bible quite clear, regardless of the current “wisdom” and interpretation of the icons of our depraved popular culture. But there is still much unknown to us and many mysteries that have not been revealed to us. I have just found Hebrews 3:11 to be interesting and thought-provoking. Maybe God keeps these mysteries so that we will seek more answers to who He is and how marvelous His creation really is. I don’t have all the answers, but I like to keep searching and seeking.