Now, some have suggested that the universe is eternal, that it has existed forever. *cough, Cutup, cough* But our little reflection has shown us it's not possible that it has existed forever.
Here's why. This point in time we call "now" is actually future with reference to all of the past. We agreed you cannot get to any infinite point in the future by adding as events one to another. Therefore, this present moment in time can't represent an actual infinite number of events added one to another proceeding from the past. Time has proceeded forward from the past as one event is added onto another to get us to today. But we know that whenever you pause in the count as we've done today, that you can't have an infinite number of events. Which means that there is no infinite number of events that goes backward from this point in time, only a finite number of events. Here's another way of putting it. If you can't get into the infinite future from a fixed reference point (the present) by adding consecutive events one by one, you cannot get into the infinite past by subtracting consecutive events, one by one, from a fixed reference point (the present). If you can't transverse the distance in one direction (present to infinite past), you can't transverse it in the other direction (infinite past to present).
This means that if the universe consisted of an infinite series of events in time, you could never arrive at this present moment. Philosopher Dallas Willard puts it this way: "As in a line of dominoes, if there is an infinite number of dominoes that must fall before domino x is struck, it will never be struck. The line of fallings will never get to it." ( Does God Exist--The Great Debate , p. 203-204) In other words, there would have to be an infinite number of events completed before you could get to the domino before you. But you can never complete an infinite number of events. An infinite series is innumerable by definition, so you can't treat it as if it were a number you could ever arrive at. This means the universe is not eternal. The universe has not existed forever and ever with no beginning. The universe, in fact, had a beginning. If it had a beginning, if the universe came into being, and it's not eternal, then something must have caused it that didn't have a beginning itself. The universe had a Beginner, some infinite, self-existent, uncaused, non- contingent Someone who started it all. Some kind of God must have been back there in time. I like this argument. It's a little tricky, but it shows how much work you can do with a few moments of careful reflection. And it's a good argument, by the way. It's the same Kalam cosmological argument developed by Muslim theologians during the Middle Ages that Cutup wrestles with.
Now if this argument is good, then our conclusions should match the world as we discover it. And science has demonstrated this particular thing to be true: because science has demonstrated with Big Bang cosmology that the universe did have a beginning, prior to which there was nothing physical. Science has shown that time and matter and energy all had their beginning at a point called the singularity. Prior to that, there was nothing physical. The universe came into being. That raises some very interesting questions about how such a thing ever happened to begin with.
Let me just bring this out of the intellectual stratosphere for a minute. When talking with an atheist one can ask, "OK, if God doesn't exist, where did everything come from? Obviously something is here. Where did it come from? Why is there something rather than nothing at all?" He says, "I don't know, I'm not an expert. I don't know all the answers. You're the one with all the answers." You say, "Wait a minute. It's not that hard. There aren't that many options. Either everything always was here or it wasn't always here. The Law of Excluded Middle says it's got to be one or the other. Can't be neither. Can't be both." Well, we know that the universe wasn't always here because of this little exercise we did. It's impossible to accomplish an actually infinite series of events by adding one to the other. Further, science seems to make the point very clearly from what we know in cosmology and astrophysics, astronomy: the universe had a beginning.
So we are stuck with a universe that began. It wasn't always here; it came into being. Now, it either began by itself, in other words, it created itself, or something else caused it to happen. Things can't create themselves and here's why: In order for a thing to create itself it would have to be the cause that caused itself as an effect. We have cause and effect. You make a pie. You making it is the cause. The pie is the effect. In this case, we'd have to say the pie made itself which means it is its own cause even though it is the effect. This would mean it would have to exist to cause itself before it existed as an effect. It would have to exist and not exist at the same time. That's absurd. Therefore, it must have been caused by something else. Now what caused it? It would have to be something that itself wasn't caused, or else you would run into the same problem we started with. So just with a little thinking here, we come to the conclusion that everything wasn't here, and so something must have caused it--and it would have to be something that wasn't itself caused but was eternal. A little more thinking and you could come to the conclusion that it must be personal as well, because the cause has to be greater than the effect, and the universe has personal elements in it, so therefore the cause must be personal as well.
That's pretty easy, I think. Where did everything come from? Well, there are not too many options. One can move from there to the fact that there must have been some kind of intelligent first cause: Aristotle's unmoved Mover. This doesn't automatically prove the God of the Bible, but it is a beginning. Now if an atheist rejects this, then what is he committed to? He is committed to either saying that everything always existed, for which there is no evidence. None. Zero. Zip. Or he has to say that everything came from nothing, for which there is no evidence. None. Zero. Zip. Now who is the person who is taking the wild leap of faith?
Edit: source for this arguement and other such apologetic arguements on various issues can be found here:
http://www.str.org/site/PageServer. Credit where credits due.
