Well, it's impossible to make something out of nothing now, so why would it be possible then? With the smallest atom, which is very much a something, I can create millions upon millions of objects, but without it or anything else, I can create nothing.
And even if it was possible to create something out of nothing back then, something must have altered the laws of reality to do so. To say that nothing can alter the rules of reality so that nothing could make something would mean that nothing was something. Because nothing can't do anything.
To say that God made the universe would say that something made something, but since God is something, He must have been made from something else, right? In my opinion, no. To some, God is a being that is not bound by the rules of reality that He created and is thus able to alter anything he desires. In my opinion, we are bound by that reality, and God is bound by His own reality.
Think of it as a video game. We are not bound by the rules of the game, but the characters we control and play as are bound by their own reality. This can also be applied to the creation theory. Mario could not exist unless Miyamoto was there to create him. Something must be made from something, and God is the ultimate/final gamer without anyone to create Him (I know that sounds weird, but this is the best way I can explain it).
The only other explanation is that something was made from nothing, and science has demonstrated that matter cannot be created from nothing. Because God goes beyond our reality, He has the ability to do so. One could argue that God does not exist, and that matter was created from nothing, but like I said, that is impossible. And if it were possible, then why or how were the rules of reality altered out of nothing? That would mean that nothing can do everything, but the truth is it can't. It is nothing. Nothing can only create nothing, which would mean that the odds of nothing creating the universe and the world as we know it are infinity to 0.
God's omnipotence/existence can be explained, even when there is evidence against His existence, by the big rock theory. Let's say God created a rock that was so heavy that even He could not lift it. That would mean that He is not omnipotent because He can't lift the rock. If He created a rock so heavy that he could not lift it, but lifts it anyway, that would mean that the rock is not as heavy as proclaimed, which in turn means that God is not omnipotent because He did not create a rock so heavy that He could not lift it. However, to say that the rock is heavy means that it is bound by the laws of gravity/weight/mass...basically laws that govern our reality. However, God is not bound by the laws of reality that He created. If we created a rock so heavy that no human being could lift it in a video game, we'd still be able to lift it by lifting our TV because we are not bound by that reality. Sure, Mario wouldn't be able to do it, but that's because he is bound by his reality. God can do anything in our reality because His reality is different than ours. It is a reality that goes beyond our comprehension, and when we die I believe we become a part of that reality. Death is breaking free of our reality and coming to terms with another. I know that all of this sounds almost too fantastic to be true, but God exists because nothing can't come out of nothing. It is the rules of our reality and the known universe.
Basically what I'm trying to say is that in our reality, it is not possible to create anything out of nothing. If it were true, then I could create a living being out of...well, nothing! In God's reality, it is possible to create something out of nothing because it is a reality that is governed by totally different rules. From that reality, He was able to create our reality and it's own set of rules. To say that God's reality does not exist would say that our reality created itself; our reality did not create itself because our own laws forbid it.
This isn't meant to be offensive to those who don't believe in God, it's just some food for thought. If you don't want to debate, then just pass by without comments like "Thank you for making me uncomfortable" or something like that. Otherwise, a rebuttal would be nice. This is a forum board, right?