Let's suppose you start counting the steps of the walking man. Count, and add one step after the other. 1,2,3,4 and so on. The man keeps walking, and you keep counting his steps. Whenever he stops, the number of steps that you count is finite. The man can walk a thousand years or a billion years. The number of steps he walked is always finite, never infinite.
Now imagine that our man started walking back past in time, reached now, and stops. Now, this point of time in the present is a point of time future to all past. Correct? In other words, we are future to yesterday. Now, some have suggested that the universe is eternal. But 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 right now, that you can't have an infinite number of past events. Which means that there is not an infinite number of events that goes backwards from this point in time.
Only a finite number of events did pass. Which means the universe is not eternal. Which means the universe has not existed forever and ever with no beginning, but in fact, had a beginning.
Philosophical reasons why the universe nor quantum effect potentials cannot be past eternal
If we are starting to count from now. Whenevever we stop counting, and look back, there is always a finite number that was counted. If we stop counting after one million, it is a finite number. A trillion. Finite. it is impossible to complete an infinite series by addition. The series of past events is complete. The same is with time. If we start counting from now, whenever we stop, a finite timespan has past. We realize that we can never get to an infinite period of time in the future by adding individual events together. Now, today, this point of time in the present, is a point of time future to all past. Correct? In other words, we are future to yesterday, and the day before that. Some have suggested that the universe is eternal. That it has existed forever. But that is not possible for precisely that reason.
This point in time is actually future with reference to all of the past. We cannot say that any particular point in the future will accomplish an actual infinite as events are added 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 not an infinite number of events that goes backward from this point in time. Only a finite number of events. Which means the universe is not eternal. Which means the universe has not existed forever and ever with no beginning, but it in fact had a beginning.
It is claimed that Virtual particles are indeed real particles. Quantum theory predicts that every particle spends some time as a combination of other particles in all possible ways. Quantum mechanics allows, and indeed requires, temporary violations of conservation of energy. So they are in time, in space, and require a quantum vacuum, in the lowest state of energy. So we have to ask: What caused the energy, space, and time in which these particles pop up?
Imagine that you see dominoes falling, one knocking over the next, as this series of falling dominoes comes into your room. Like a person can never finish counting to infinity, an actual infinite number of dominoes could never finish falling. Therefore, if an actual infinite number of dominoes had to fall before getting to your door, then the falling dominoes would never reach your door. In the same way, if an actual infinite number of minutes had to take place before yesterday, time would have never reached yesterday, much less today. Therefore, just as there had to be a finite number of falling dominoes, there also had to be a finite—not infinite—amount of time before today. An infinite past is impossible. Time must have a beginning. And if time had a beginning it must have had a cause.
You will not live for an eternity. Are you ready for this? Boy, that sounds weird. That doesn't sound like Christianity to me. That sounds like an annihilationist, or something. I think you will be forever and ever with God in heaven if you're a Christian. Or if you reject the forgiveness that God offers through Jesus Christ, then you will pay for your crimes against God forever and ever in a place of punishment. But even though you will do that forever and ever, you will never do that for an eternity. How does that work?
Think about it for a moment. Are numbers potentially infinite? Yes, sure they are. They can go on forever and ever. Potentially the quantity of numbers is infinitely large. There's no end to them in that regard. Now, how do you ever get to an infinity of numbers actually? Well, you can start counting. One, two, three, four, five, billion one and billion two. A zillion one, two. A quintillion one, two..... Keep going. Do you realized that at any particular point in time as you keep adding one number after another, which potentially could go on forever, that you have never really accomplished that feat. You have never really gone on forever, have you? You've just counted a finite series of numbers. It gets bigger and bigger, of course. But at every particular point that you happen to be counting at, your count describes a finite number. Will you ever get to eternity by counting, adding one number onto another? The answer is no, you won't. That is why I can say that you will never live for an eternity.
You started at some point in time, and time has added to your existence, one event upon another. But as you go forward into eternity, at any particular point, if you clock your cosmic age, you will always be some age. From the time you started, to the time you're at. Now you will keep going on forever and ever but no matter how long you continue going on forever and ever you will still have an age, a particular age identifying the length of time of your existence. That particular age will never be an infinite amount. Do you see how that works? This is why you can never count to infinity because infinity is not a number, a particular number. Every stage along the counting process you are always describing a finite number, even though it gets larger and larger as you count. You will never live to eternity even though you live forever and ever and you never cease to exist, because at any point you will still have an age, even though the age is getting larger and larger as you move deeper and deeper into eternity.
This is why, by the way, I think eternal life in the Scriptures is not identified principally as a quantity of time, but as a quality of time. Look at John 17:3. Remember the great high priestly prayer of Jesus? He says, "And this is eternal life: that they may know thee, the only true God and Jesus Christ whom thou has sent." Notice the focus on eternal life there is not how long you're living as if you were actually accomplishing an eternity of existence. It's on the quality of life you live forever and ever. Knowing God and His Son, Jesus Christ. Because you can't accomplish an actual infinity with regards to time which would be an eternity. It can't be done. Why? Because you can only move towards eternity by adding one upon another and you can never add one upon another and accomplish an infinite number of things. In this case, an infinite number of events that transcribes an infinite period of time. This is what is called in philosophical circles as the problem with accomplishing an actually infinite series of events by simply adding one event to another.
As we've done our little mind experiment here, our experiment in thinking and reflection on the nature of eternity and how one gets there, we realized that you can't really get to eternity by adding events together, one upon another. Because at every point you still have a finite number, even though it is much larger than it used to be. In other words, time proceeds forward as one event is added to another and that time that proceeds forward is always a finite amount of time. Do you see that? Now if you grasp that, and it's not really as hard as it may seem at first, I am just simply saying that when you count numbers are potentially infinite, but you can never count to infinity because you can't get there by adding one number after another because at any point in your count you are still dealing with a finite number. The same applies to events in time Which means with regards to your eternity, though you will live forever and ever, you will never live for an eternity. Because you cannot accomplish an eternity by adding one event upon another.
Now this has very significant applications for the concept of the existence of God. It's really quite simple. Our little experiment took us from the present into the future. We realize that we can never get to an infinite period of time in the future by adding individual events together. But today, this point of time in the present, is a point of time future to all past. Correct? In other words, we are future to yesterday, and the day before that. Now, some have suggested that the universe is eternal. That it has existed forever. But it is not possible that it has existed forever. Here is the application. This point in time is actually future with reference to all of the past. We just agreed that you cannot say that any particular point in the future will accomplish an actual infinite as events are added 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 not infinite number of events that goes backward from this point in time. Only a finite number of events. Which means the universe is not eternal. Which means the universe has not existed forever and ever with no beginning, but it 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 itself have a beginning. It had a Beginner. Some infinite, self-existent, uncaused, non-contingent Someone who started it all. Some kind of God must have been back there. I kind of like that argument. It's a little tricky, but it shows what you can do - and it's a good argument by the way - it's basically the Kalam cosmological argument actually developed by Muslim theologians during the Middle Ages. It shows how much work you can do just by simple reflection. If the work is good on simple reflection, of course, it should match the world as we understand it, 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. That time and matter and energy and motion 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. I'm not going to carry it further at this time. Others have done so and we've talked about this at other times. You chew on that for awhile.
Let me just bring this out of the intellectual stratosphere for a minute. You are talking with an atheist. You ask the atheist, 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. Because there are not too many options. Either everything was always 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 it wasn't always here because of this little exercise we did. The impossibility of an actual infinite series of events adding one on the other, like we see happening in our universe now. And also, science seems to make the point very clearly from what we know in cosmology and astrophysics, astronomy is that the universe had a beginning. So we are stuck with a universe that began. So it wasn't always here, it began. 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. Which 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 is 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. 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. You can move from there to at least the fact of some kind of intelligent first cause. Aristotle's unmoved Mover. You haven't proven the God of the Bible, but it is a beginning. Now if an atheist rejects that 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 leap of faith?