I assure you, this is not a game.
You begin with an assumption, when you say, "If God created the universe from pre-existent matter...." Matter is the substance of the material universe, what we call the natural world. But the material universe is not all that God created, and probably only an infinitesimal part of all He has created. We know He created everything, which includes not only the material universe, but all of the supernatural, or what the Bible calls, the celestial realms of Angels and other wonderful subpernatural beings, as well.
Regardless of how far back you want to take it, at some point there existed only God.
This, also, I think is a mistake. When wouldn't there have been God? In fact, the idea that God is eternal means that there never was a time when God wasn't. And when was God's nature different? The Bible clearly declares that God works and creates, it is His naure (part of it, I mean). Also, you statment suggests that the works of god are done in, "time," and that some eternal things can exist before or after other eternal things. Surely you don't suppose God is limited to creating things which are not eternal, not existent in the same way he is. Then, if God makes eternal things, there would never be a state, in time or otherwise, when those eternal things which God creates and God Himself, did not both exist.
The Bible frequently distinguishes between the natural material world and the supernatural world as the seen (natural or temporal world) and unseen (supernatural or eternal world). For example, "While we look not at the things which are seen, but at the things which are not seen: for the things which are seen are temporal; but the things which are not seen are eternal. (2 Cor 4:18)
Now surely, the things which are not seen are not nothing, else what would our faith be in? "Now faith is the substance of things hoped for, the evidence of things not seen." (Heb 11:1) Certainly faith is not evidence of nothing. So the "not seen" is not "nothing."
Now the Bible clearly says, "Through faith we understand that the worlds were framed by the word of God, so that things which are seen were not made of things which do appear." (Heb 11:3) So we see, the things which are seen (that is, the material temporal world) are not made out of nothing, that is ex nihilo, but for things which cannot be seen (the eternal and supernatural).
The problem with the concept of ex nihilo is that it was derived from an amalgum of mathematical concepts and paganism. In fact, there cannot be, "nothing," and nothing can come from what is not, but must also come from something.
So long as God is, there is something. And this is another way to consider the question. You mentioned the peculiar conscept of, "there existed only God." I'll ignore the obvious implication of a temporal quality to God's existense this introduces, and ask this question, what does "only God," mean? Since we cannot say, "was there a time when God had not yet created anything, since that suggests God exists with temporal limits, which we know is not true, what can we say? Is there some sense in which, in some mode, God can be called existent even thought there is nothing else existent, so that we would have to describe God in this imagined mode as existing nowhere doing nothing ....
It is inconceiveable. It is absurd. It is not possible for God to be and for nothing else to be, unless God were unable to be the source of all that is, and there were nothing else. If God is, there is always all that is eternal with Him.
The material world had a beginning, because the material world is temporal and constrained by the laws of material existence. The supernatural world of which God is the source, and it all "springs" from him is eternal. That does not mean that everything in the supernatural realm is eternal, but that the realm itself must be, else it could not be God's realm.
The natural world is a subset of the supernatural world, and was (as a technical explanation) differentiated from the supernatural world by the imposition of those qualtities we call the spatial/temporal(physical)laws of nature.
If you say God made the material world out of nothing, it makes God nothing.
Acts 17:28 For in him we live, and move, and have our being; as certain also of your own poets have said, For we are also his offspring.
Col. 1:17 And he is before all things, and by him all things consist.
Hank
It is inconceiveable. It is absurd. It is not possible for God to be and for nothing else to be, unless God were unable to be the source of all that is, and there were nothing else. If God is, there is always all that is eternal with Him.
I admittedly have a difficulty with this from a logical standpoint. Here's why. The very act of creation carries with it a 'before' and 'after.' Otherwise they were not created...they simply were. You and I were clearly created. We are promised eternity with God, meaning that we shall be with Him eternally...going forward. Do you maintaint that our souls pre-existed our incarnation? Satan had to already exist at the point of creation. Satan cannot have been in the bottomless pit while simultaneously appearing in Eden.
I think we're off on a tangent here, but it raises some interesting questions. I certainly maintain that God not only creates but sustains all things.
Classical Hank, so deep nobody gets you. :)
As I understand it, God made the created world, including the seen and the unseen, out of Himself. When the physicists "discover" that the mysterious black matter of the universe is really light, call me. Always a delight to see your mind at work. JS