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Why Belief in God is Reasonable

Our skeptical age asks why we should believe in God at all. Part of the answer is that this belief is built into our nature.

No matter who you are or where you’re from, the desire to be happy is one thing we all have in common. Some things—food, fun, being with friends—make us happy superficially. But these pleasures come and go.

Many are able to find longer-term happiness with family, but families bring their own challenges, and many people go through times of familial disappointment and hardship. Ultimately, all of us are confronted with an inescapable reality: one day we will die, and this fills us with dread.

When we contemplate the end of our lives, we must ask serious questions: Is there nothing more? Is life, as Shakespeare’s Macbeth said, just a tale “full of sound and fury, signifying nothing”?

Two thousand years ago, the most influential man in history, Jesus Christ, preached good news from God to the people. Only by embracing God—the source of all happiness—could they find eternal happiness.

But God is infinitely above us. He is all-knowing and all-wise. “For as the heavens are higher than the earth, so are my ways higher than your ways and my thoughts than your thoughts” (Isa. 55:9). Thus, God sometimes has things to tell us that go beyond all human expectation.

Sometimes people struggled with things Jesus taught, finding them to be “hard sayings” (John 6:60). Some even turned away from his preaching. When Jesus asked his core disciples, “Do you also wish to go away?”, St. Peter said, “Lord, to whom shall we go? You have the words of eternal life” (John 6:67-68).

This is exactly right. It is Jesus who has the words that bring eternal life. We must listen to him, for there is no one else to whom we can go if we want to find eternal happiness.

Everything begins with God. He is the Creator, and so he was there “in the beginning.” But today we live in a skeptical age, and some ask why we should believe in God at all. Part of the answer is that it’s built into our nature. Religion is a human universal. It appears in every culture through the entire history of the world.

Human nature as a clue

The two fundamental ideas in religion are the divine (God or the gods) and the afterlife. Every religion has teachings about one or both of these. There never has been a people that disbelieved in the divine and the afterlife. In the twentieth century, some
totalitarian regimes tried to ban religion, but it didn’t work.

Religion is built into our nature. To be religious is simply to fulfill your human nature rather than resisting or ignoring it.

The twin desires for the divine and the afterlife, which appear in every time and land, are powerful pointers to their reality. There really is a God, and desire for him is so strong that, if denied knowledge of the true God, people will invent new ones to fill the gap. The desire to be with him is so strong that people recognize it can’t be satisfied in this life, which points to life after death.

‘In the beginning’

We can say more about God’s existence. Some scholars have proposed an argument based on the fact that things have beginnings. Whether it’s a cloud, a rock, or a baby, everything in the universe has a beginning.

These things did not come out of nowhere. There were reasons why they came to be. Evaporating water forms clouds. Lava cools to make rocks. And, of course, a baby has parents. Not only does everything in the universe have a beginning, there is a reason why it began.

We call these reasons causes, and the quest to understand causes is one of the main goals of science. Scientists have discovered causes for many of the phenomena in nature, but the overall, guiding principle is the powerful human intuition that things have causes. When something begins to exist, there is a reason why.

Some thinkers have used this fact to argue for God’s existence like this:

  1. Everything that has a beginning has a cause.
  2. The universe has a beginning.
  3. Therefore, the universe has a cause.
  4. The cause of the universe is a basic definition of God.
  5. Therefore, God exists.

Sometimes people respond by saying, “If everything has a cause, what caused God?” But this is a misunderstanding. The argument doesn’t claim that everything has a cause but that everything with a beginning has a cause. God doesn’t have a beginning, so he doesn’t need a cause.

The fact God has no beginning is an important part of the Christian faith, and this argument is based on the Christian teaching that “In the beginning God created the heavens and the earth” (Gen. 1:1).

Does the argument work? The first premise—that everything with a beginning has a cause—is the powerful human conviction that drives scientific inquiry.

Another premise—that the world’s cause is a basic definition of God—is simply a definition, and so it doesn’t need to be proved any more than definitions like “a bachelor is an unmarried man” or “a triangle has three angles.” These are true by definition.

Of course, a single argument can only do so much. But if it’s true that the world has a cause, then it’s legitimate to understand that cause—whatever it is—as God. The question at that point would not be “Does God exist?” but “What kind of God exists?” To build a full picture of God, this argument would need to be supplemented with others to reveal more aspects of his character.

The key part of this argument is the second premise—that the world has a beginning. If that’s true, everything else follows. Do we have evidence of such a beginning? Yes, and we’ve had it for a long time (see sidebar).

In 1927, the Belgian astronomer and priest Fr. Georges Lemaître realized that Einstein’s theory of general relativity suggested that the universe should be expanding, which meant it would have had a beginning. At some point in the past, everything would have been compressed into a “cosmic egg,” as Lemaître put it. He theorized that this material then expanded outward to form the universe as we see it, and the Big Bang theory was born.

Soon it was confirmed. Using new telescopes and tools, astronomers began to measure the light from distant galaxies and discovered they were moving away from us. What’s more, the farther away the galaxies were, the faster they were moving away. The whole universe was expanding! More confirmations of the Big Bang followed, and today it is the accepted view in astronomy.

In 1951, Pope Pius XII hailed these discoveries:

It would seem that present-day science, with one sweeping step back across millions of centuries, has succeeded in bearing witness to that primordial “Fiat lux” [Latin, “Let there be light”] uttered at the moment when, along with matter, there burst forth from nothing a sea of light and radiation, while the particles of chemical elements split and formed into millions of galaxies (“Address to the Pontifical Academy of Sciences,” Nov. 22, 1951, n. 44).

Science had discovered that the universe had a beginning, and thus a cause—meaning that God exists.

Why does anything exist at all?

The results of science are always provisional, so they can change as new evidence is discovered. We thus shouldn’t rest our faith simply on what today’s science suggests.

We should ask more fundamental questions, like whether we can show God exists in a way that doesn’t depend on changing scientific ideas. That puts us in the realm of philosophy, which deals with fundamental principles that are always true.

Many philosophical proofs of God’s existence have been offered, and some are quite complex. Here we will look at a simple one that is easier to understand. It begins with the question: “Why does anything exist at all?” This is another expression of the powerful human intuition to understand causes.

When we look at the world around us, we see many things that change. For example, at one time a man may be standing, but at another time he may be sitting. Yet he is the same man. Philosophers express this fact by saying the man’s posture is contingent, meaning that it could be different than it is. Humans are contingent beings, because they could be different than they are at any given moment.

The same is true of everything we see in the universe. Living things like people, animals, and plants all grow and develop. Inanimate things like your car, phone, or computer may be turned on or off. Even rocks and gems can be cut, polished, or moved from one place to another. All the things in the physical world are contingent; they could be different than they are.

But is everything contingent? Let’s consider a specific thing—let’s say, a man who is standing. Why is he standing now?

This question can be answered different ways. You might appeal to something in the future (he’s standing to reach something on a shelf) or to something in the past (he just got out of bed), but we’re not interested in these. Forget the past and the future and focus only on the present moment: why is he standing right now?

You could say, “Well, he’s tensing certain muscles in his body to stand.” True, but we can go deeper. On a more basic level, there are chemical and electrical processes in his cells that cause the right muscles to tense. And we can go further yet, down to the level of atoms and the particles that make them up. If we wanted, we could explain why the man is standing in terms of the positions of all the particles in his body and the forces governing how they interact.

This is the deepest kind of explanation science can provide currently, but we can still ask questions. Why do these particles exist at all? Why don’t they just disappear?

Contingency and necessity

Scientists have proposed principles dealing with the conservation of mass and energy so that the atoms in the man’s body continue to exist. They’ve also proposed forces that govern the interactions of the particles in the atoms. Currently, there are four known forces: gravity, electromagnetism, and the strong and weak nuclear forces. These forces obey rules or laws of their own.

But our curiosity still isn’t satisfied. Why do principles such as the conservation of mass and energy hold? Why are there four fundamental forces? Why do they obey one set of laws and not others?

One day it may be possible to explain the current laws of physics in terms of a deeper, more fundamental set of laws. But this would only push the question back one level, because we’d need to ask the same questions about any newer, deeper principles: why are they the way they are and not some other way?

At some point, we must hit a fundamental explanation for why things are the way they are. This fundamental explanation would be one where it no longer makes sense to ask, “Why is it this way rather than another way?” It would not be an explanation that is contingent but one that is necessary—something that couldn’t be different than it is. And the first and necessary explanation for why things are the way they are is a basic definition of God.

The alternative would be to say that there is an infinite regress of explanations, with each level needing to be explained by something deeper. For some, this might seem a poetic idea, but there are problems with it.

A principle applied in both science and philosophy is Occam’s razor. It holds that we shouldn’t needlessly complicate explanations. In other words, we should use the simplest explanation that fits the evidence. Since we don’t have evidence for an infinite regress of explanations, where every proposed explanation needs to be clarified by a deeper one, Occam’s razor would say not to complicate things more than needed and to instead infer that there is an ultimate, fundamental explanation for the world and the things in it.

Another problem with the idea of an infinite regress is that, in the end, it wouldn’t explain anything. Such a regress would not provide us with an ultimate explanation—because there could be no ultimate (last, final) explanation. The world would thus be left unexplained, with no bedrock on which the whole of reality rests.

Like our previous argument for God’s existence, it’s important to note what is not being claimed. It is not being said that everything needs a cause or explanation. That’s the whole point of finding an ultimate or fundamental one.

We’re only seeking explanations for contingent beings—things that could be other than they are, like a man who could stand or sit. Everything we see in the physical world is contingent, and to explain why these things exist and are the way they are, we need to go beyond the physical world to find an ultimate explanation.

This final bedrock to reality does not need a further explanation. It’s not a contingent being but a necessary one—something that simply must exist. By definition, God does not need a cause or explanation. He is the First Cause and Ultimate Explanation.

The Christian view of God

No one argument tells us everything about God, but as we consider different ones, we get new parts of the picture.

The first argument we considered—that human nature has an inbuilt desire to enter into a relationship with the divine in a way that can’t be satisfied in this life—points to the fact God is capable of having relationships. He isn’t an impersonal force with no mind or will but is capable of loving relationships with his creatures. It also points to him being supremely intelligent, so he can have relationships with the staggering number of people who exist and have ever existed.

The second argument—that the beginning of the universe shows the existence of God—reveals that he is immensely powerful, because he brought the universe into being.

And the third argument—that God is the ultimate explanation for why the universe is the way it is right now—points to the fact that he still exists and that he could not be other than he is, for he is a necessary Being.

We thus build up a picture of God as an all-knowing (omniscient), all-powerful (omnipotent), all-loving (omnibenevolent), and necessary Being who cares for his creatures and enters into relationships with them.

Philosophers and theologians have developed arguments that further flesh out our understanding of God. Among them is the idea that God doesn’t just have perfect knowledge, perfect power, and perfect love. He has all possible perfections. Whatever perfections are possible, God has all of them in an infinite degree, including the infinite happiness that he has always possessed in heaven.

Such an omni-perfect Being has no needs. As creatures, we have a need for God—for him to create us and sustain us in existence. But he has no need of anyone to create him. Human nature contains an inborn need for union with God, but God does not need union with us. He is already infinitely happy and doesn’t need our worship or our prayers. Jesus points out God knows what we need before we even ask (Matt. 6:8).

Consequently, God didn’t need to create the world. His infinite happiness is part of who he is, and he would have been just as happy if he never created anything. So, why did he? The answer is that he didn’t do it for himself. He did it for us. The Catechism of the Catholic Church explains:

We believe that God created the world according to his wisdom. It is not the product of any necessity whatever, nor of blind fate or chance. We believe that it proceeds from God’s free will; he wanted to make his creatures share in his being, wisdom, and goodness (295).

The infinite, all-loving God thus freely chose to create the world, including us, that he might share his love and goodness with us. And his love for us does not stop with the mere fact of creation. It continues with his desire to share his perfect and eternal happiness with us in heaven.

But that’s another article for another issue.

Sidebar: The Big Clue of the Night Sky

Suppose the universe did not have a beginning and stretched infinitely far back in time. What would the results be?

When we look out at the night sky, we see that it’s filled with stars. And the deeper into space we look with our telescopes, the more stars and galaxies we see. We’re surrounded by a sea of innumerable stars.

So, why is the night sky dark?

Think about it: if the universe always existed, light from even very distant stars should have reached us by now. The light from every star in the heavens should have reached us after infinite time. And since we’re surrounded by them, the whole sky should be blazing with light from all those countless stars. We should look up, even at night, and see a wall of light that is bright like the face of the sun.

But that’s not what we see, and it’s a clue that the universe is not infinitely old but had a beginning.

Men wondered about the problem of the night sky for centuries. One was the German astronomer Heinrich Olbers (1758-1840), and scientists often called the fact the night sky is dark “Olbers’ paradox.” Those who held the universe had no beginning found it hard to resolve the paradox. In the twentieth century, with Fr. Georges Lemaître’s discovery of the Big Bang, it became even harder.

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