Why even ask or attempt to answer this question? Doesn’t everyone think God exists? Well, sort of -

There are atheists and agnostics. Sometimes even famous ones change their minds. In 2004 Antony Flew, who is a very famous philosopher, announced that he had abandoned the atheism he had held to since age 15 and was now a deist.

But this shows that you can believe in God while avoiding the Christian faith. We are trying to move beyond just believing that there is some kind of God to the truth of the Christian faith. To evaluate the evidence for the Christian faith we have to start with evidence that there is a God.

Why not just go to the Christian faith? The problem with jumping directly to Christianity and the Bible is this: if we have no good reasons for thinking God exists, all the key events in the Bible are very unlikely.

For one big example, all that talk about resurrection from the dead is just nonsense unless we know God exists. So, what evidence points to the existence of God?

Evidence for the claim "God exists" -- there are several lines of evidence here. Some are probably stronger than others. They are each a thread that, when woven together will all the others, forms the rope of evidence for the existence of God.

Things that "make no sense" apart from the existence of God

I am thinking, here, of a style of argument that goes like this:

We are all aware that my automobile is well-maintained.
We are all aware that I am a terrible auto mechanic.
So there must be someone who helps me keep my automobile in such good condition.

There are some aspects of human existence that few are willing to deny. Some of these make no sense unless God exists. What kinds of things do we have in mind here?

If God does not exist, how do we make sense of any strong sense of "ought"?

Without debating the details of systems of ethics or particular sets of morals, it is still the case that almost everyone agrees some "oughts" are obligatory for humans beings.

Perhaps you can think of examples of these kinds of "oughts." Even very bad people seem to display these. This sense of "ought" seems to transcend history and geography -- it seems to be found at all places and at all times.

We can wonder how to account for the existence of "ought." One response is to say, "It's just the way human beings have evolved." If that is true, then the sense of "ought" is very much like being hungry -- we have it just because of the way we are. But if that is all it is, it really is not a sense of "ought." It is a like a hunger pang.

Consider an example:

Suppose we take the claim, "One ought not take a living human infant and toss him into the fire for sport." Someone might say, "There have been people who did not accept the truth of that claim." But wouldn’t your immediate response be, "Well, if one does not accept the truth of that claim, one ought to!"

You see how this matter of "ought" seems to be unavoidable.

Sometimes advocates evolutionary ethics claim that certain moral habits helped people survive, and therefore those moral habits survived and won out, so to speak. Perhaps, but that is not even in the ballpark of a true "ought."

Some would give a utilitarian account of this. That is, "the greatest good for the greatest number" demands that we avoid tossing living infants into the fire. But we could ask, "WHY ought we seek the greatest good for the greatest number?"

Or, others would claim that we ought to seek the greatest personal pleasure. But why ought we seek pleasure? Some hedonists would say, "It simply is a fact that we do seek pleasure." But, we can still ask, "Ought we do so?"

So one way, the best way, perhaps the only reasonable way, to account for this matter of "ought" is the existence of a Creator of the physical universe who is separate from the physical universe.

If God does not exist, why should anyone be "reasonable"?

This next point, though somewhat like the last one, starts from a different place. Imagine a theist and a non-theist debating. The theist presents arguments for the conclusion "God exists." The non-theist attacks those arguments and presents counter-arguments.

Consider what is being assumed by both parties to this debate. Both assume that a good argument has some kind of power to change someone else's mind. Everyone, it seems, makes this assumption -- otherwise we would just keep these arguments to ourselves.

Now, let us ask another question: are both parties to the debate over the existence of God justified in assuming that good reasoning should change someone's mind?

The theist has good reason to make this assumption. The theist holds that a personal being with a mind (God) is the originator of the universe, including human minds. According to the theist, when human beings reason correctly, their minds are following a pattern taken from the mind of God.

What can the non-theist say about this matter? That goes back to what the non-thiest must say about the nature and origin of human beings. Human beings must be the product of random arrangements of matter and energy in space. Thus, the reasoning ability of human beings must also be the result of pure chance -- an accident. It is very difficult to see how this gives the non-theist any justification for attributing some compelling nature to human reason. Likewise, the non-theists counter-arguments to theism are, by the non-theist's own assumptions, the product of chance.

So here is something else -- the assumption that reasoning has some mind-compelling power -- that seems best explained by the existence of the transcendent mind of the Creator of the material universe.

Features of the universe best accounted for by the existence of God

The Origin of the Universe

If there is some reason to think that the universe had a "beginning moment" then there is some reason to think that the universe had a beginning, and thus a cause of its beginning. Is there anything about the universe that gives some clue that the universe had a beginning?

There are several things to consider here.

First, the universe, including ourselves, seems to be constantly changing. Is there anything about this changing that points to a beginning?

Many scientists since the late twentieth century agree that there is much evidence for a "beginning moment" of the universe. This it the so-called "big bang." Even before this theory there was reason to think the universe had a beginning point.

The Second Law of Thermodynamics implies that energy available to do work will always tend to decrease. This is often called "entropy." Entropy is a measure of randomness, and in a "closed system" (one in which there is no outside force to counteract the decay) entropy (randomness) increases. If that seems too complicated, think of it like this: charged batteries tend to discharge, and without some outside source of power a battery can’t be re-charged.

If this is correct, then there are two possibilities.

The first is that the universe, taken as a whole, is NOT a closed system. This would mean that there is something "outside" or "beyond" the universe, which would certainly be at least a move in the direction of theism. Back to the battery: if the battery gets recharged that shows there is a power source outside the battery.

The other possibility is that the universe is a "closed system." If this is the case, an interesting conclusion emerges. A universe that had "always been here" should be in a state of maximum entropy. The universe we observe is NOT in a state of maximum entropy. (That is, there is energy available to do work.) Thus, the universe has NOT always been here, that is, it had a beginning. Or, a battery that still has a charge hasn’t been here forever.

Even before "big bang" theories and "laws of thermodynamics" came along, both Arabic and Jewish philosophers had reasoned along these lines:

Before any given moment (or any period of time you care to use) could arrive, an infinite number of prior periods of this length would have to be elapsed - think of this as crossing or transversing a period of time - if time were infinite.

The infinite cannot be transversed.

Therefore, no given moment could arrive.

But this is absurd, so time is finite.

This implies the same conclusion as is implied by modern science: the universe had a beginning. (You might be familiar with the idea that a line consists of an infinite number of points, and yet we can "cross" all those points if we walk from here to there. But remember that lines and points are simply assumptions of geometry - they are not real, existing things.)

Anything that had a beginning must have had a cause that existed before it began. In this way, we reason to the existence of an Originator of the universe.

Robert Jastow, an astronomer, made quite an impact in 1978 with the publication of his book God and the Astronomers. (Jastrow also was instrumental in translating evidence regarding the "big bang" into language that the non-scientist could understand.) Here are a few particularly interesting excerpts from Jaswtow's book:

p. 1 "When an astronomer writes about God, his colleagues assume he is either over the hill or going bonkers. In my case it should be understood from the start that I am an agnostic in religious matters. However, I am fascinated by some strange developments going on in astronomy -- partly because of their religious implications and partly because of the peculiar reactions of my colleagues."

p. 101 "Now three lines of evidence -- the motions of the galaxies, the laws of thermodynamics, and the lifestory of the stars -- pointed to one conclusion; all indicated that the Universe had a beginning."

p. 105 "For the scientist who has lived by faith in the power of reason, the story ends like a bad dream. He has scaled the mountains of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries."

Continued existence argument

There is a line of argument for the existence of God that goes back to ancient Greek philosophy -- especially Aristotle. (It is also implied in the O.T. writings.) It starts by considering, not a beginning point of the universe, but just the fact that there now exits something rather than nothing.

One of the key assumptions of this kind of argument is what is called "the principle of cause and effect." This principle says that when we observe anything -- motion, change, the existence of something -- anything at all, we are justified is assuming that this effect has a cause to account for it. But it also implies that while many things are both causes and effects, not everything can be both cause and effect. Somewhere the chain must end, with something that is a cause, but not an effect.

So suppose I take notice of the existence of myself and/or the world around me. But both myself, and the world I observe around me, are changeable, in fact changing, decaying things. So the principle of cause and effect requires that I assume that I and the world around me has a cause for its continued existence. Perhaps there are a whole string or hierarchy of such causes.

But even such a string of causes cannot consist of only causes that are also effects -- this would not account for the existence of the string of causes as a whole. So I am forced to conclude that there must exist a cause that itself has no cause -- the so-called "uncaused cause."

One way to try to escape this argument would be to just abandon the whole idea of cause and effect. But to abandon cause and effect would be to abandon the very possibility of understanding the world around us. Few are willing to do this -- and so we remain "stuck" with the implications of cause and effect for the existence of God.

Order of the universe argument

There have been many versions of the argument that begins with the apparent order of the universe and concludes that God must exist to account for that order.

Of course, with the rise of Darwinism, many thought arguments from order for the existence of God were dead. What appeared to be "order" was simply the result of natural selection and adaptation.

Then the 1960s rolled around, and it was shown that all living things contain information encoded in DNA. This alone might not have revived the argument from order. A good Darwinian could simply say that the information in living things was the product of many accidents over a long period of time.

Except that, about this same time, because of the rise of computer science, a lot of work began to be done with information theory. In working with the coding and decoding of electronic messages, we have found that information cannot just "happen." Information requires an intelligent source -- randomness destroys information.

This means that we, and all living things, being filled with information in our genetic codes (even the simplest of organisms contain vast amounts of information in the DNA), point to the existence of some self-existent source of information.

Conclusion: This presentation has been far from short, and we have only scratched the surface. One of the better summations of the case for theism has been given by Richard Swinburne, who, after examining in great depth almost every conceivable line of evidence, says in his book The Existence of God,

The only plausible alternative to theism is the supposition that the world with all the characteristics which I have described just is, has no explanation. . . That however is not a very probable alternative. (pp. 287 & 290)