If the sentence "god made everything out of nothing" is true then existed nothing before god made the worlds.
Space and time (aka our existence) is not his existence, so I cannot agree that nothing existed before space and time were created. Only that our existence did not exist before space and time were created. Which BTW science tells us that the matter in our bodies were present for the creation of space and time.
Was space and time created from nothing? Good question. I believe that space and time were willed into existence. I believe that Mind, rather than emerging as a late outgrowth in the evolution of life, has existed always as the matrix, the source and condition of physical reality - that the stuff of which physical reality is composed is mind-stuff. It is Mind that has composed a physical universe that breeds life, and so eventually evolves creatures that know and create.