Why does anything exist? I remember asking that question at a very young age. Of course, I was given the answer that God made everything. I remember sitting there thinking diligently, "What if God didn't exist?" Then nothing would have ever been made. That means for all eternity, there would just be nothing. The idea of non-existence was something that I wasn't ready to handle at the time. I was able to suppress any fears that I might have had about not existing, because, let's face it. I do exist. So, there must be a God. I mean. without a God where could it all come from?
St. Augustine would argue that there must have been a prime mover to initiate all things. But, what made the "prime mover"? If we were to say that someone, or something else made the "prime mover", than it wouldn't be a "prime mover", now would it? So, the answer then is the "prime mover" would have always existed. I remember the first time I heard this part of the argument, my first thought was, "Then why didn't God make everything sooner than He did?" It seems like a silly question, but the more I think about it, it's not silly at all. If we were to consider time as we know it, and something existed into an infinite past, when could God begin creation? I've had a few years to ruminate on this, and now I don't believe in such a thing as an infinite past. It's as nonsensical as dividing an object up infinitely. When the Greeks thought about this they thought there must be one piece that is indivisible, one basic building block to all matter. They called this the "atom". It seems to me that time, too, must have a beginning, some starting point that you cannot go beyond.
Lawrence Krauss would seem to agree with me. In his book, A Universe From Nothing, he describes time itself as beginning at the Big Bang. This does seem to get a bit heady, I know. But, an infinite past seems to be completely illogical. I have to think that our understanding of time itself must be flawed. The more I've thought about this, I've considered how we measure time. Time, really, is measured by how matter or energy changes. In an existence before a universe, nothing exists to change, would there be any way to measure the passage of time? The more I think about the concepts of time, I feel like the idea that time has a beginning makes more sense than the concept of an infinite past.
My second thought on this is that It seems to me the concept of a "prime mover" would require time. If God can think, each thought would be a different energy state than the a previous thought. If God could change, at all, it would require the passage of time. So, wouldn't the concept of an eternal God require the existence of an infinite past?
At some point, our universe began. I am not considering other universes before ours or elsewhere in a multiverse. It has been proven that our universe did have a beginning. I believe that one fact is agreed upon by theists and non-theists alike. They might argue about how long ago this occurred and in what fashion. But, we all seem to agree that it did have a beginning. So, all we're arguing about is whether or not it would require an intelligence. Following Occam's Razor, I believe that a non-thinking, universe causing potentiality, is just as likely to have existed in any state that a Christian might argue a God to exist in before the" creation". Lawrence Krauss argues that there is physical evidence that such a potentiality does exist, which is more than we have to demonstrate the existence of a God. A thinking entity is a more complicated solution than a non-thinking potentiality. And, Occam's Razor would say that the simpler solution that can explain all the facts tends to be the correct one. This is why I am unimpressed by Christian arguments for God that are based off the existence of the universe.
But, let's be honest. We're just speculating. We don't actually know. I'm certainly not saying that I KNOW whether this potentiality is in fact responsible for the beginnings of our universe or if there's something else that we haven't even begun to think of. But, Christians are saying that they KNOW that God is what created the universe. How do they know? They read it in a book? Reading something and verifying it objectively isn't the same thing. Christian's have just as much evidence as we do, and yet they claim to KNOW something that cannot be verified. Without a way to verify a claim, "I don't know" is still the most honest answer. Everything else is just speculation.