Evidence for God's Existence
Greg Ganssle, Ph.D.
I. You Cannot Prove God's Existence
Ever since Immanuel Kant wrote his Critique of Pure Reason, it has been common for
thinking people to insist that it is impossible to prove the existence of God. In fact
this claim has been elevated to the level of dogma in American intellectual culture. The
reason I know this is considered unquestionable dogma is the reaction I get when I call it
into question. When someone says "You cannot prove the existence of God." I want to ask
"How do you know? You just met me! How do you know what I can do?"
What do most people mean when they recite this claim? Most people mean that I cannot
provide a philosophical argument for the existence of God which will convince all thinking
people. It is impossible, so the story goes, to provide an argument which will compel
assent. If my argument will not convince the most ardent atheist, I have not proven God's
existence. Since I cannot convince such an atheist to believe, my arguments do not count
as proof. If they do not count as proof, what good are they?
I agree that I cannot provide an argument that will convince all thinking people. But what
does this tell me? Does this tell me anything about God? No. This tells me more about the
nature of proof than it does about whether God exists. I cannot provide an argument which
will convince everyone, without a possibility of doubt, that God exists. That is no
problem. You see, I cannot provide an argument for any interesting philosophical
conclusion which will be accepted by everyone without possibility of doubt.
I cannot prove beyond the possibility of doubt -- in a way that will convince all
philosophers that the Rocky Mountains are really here as a mind-independent object. I
cannot prove that the entire universe did not pop into existence five minutes ago and that
all of our apparent memories are not illusions. I cannot prove that the other people you
see on campus have minds. Perhaps they are very clever robots.
There is no interesting philosophical conclusion that can be proven beyond the possibility
of doubt. So the fact that arguments for the existence of God do not produce mathematical
certainty does not by itself weaken the case for God's existence. It simply places the
question of God's existence in the same category as other questions such as that of the
existence of the external, mind-independent world and the question of how we know other
people have minds.
Does this mean that arguments for the existence of God are useless? Not at all. Sure, I
cannot provide an argument which will convince all thinking people but this does not mean
have good reason to believe in God. In fact some of my reasons for believing in God may be
persuasive to you. Even if you aren't persuaded to believe that God exists, my arguments
may not be useless. It is reasonable to believe that the mountains are real and our
memories are generally reliable and that other minds exist. It is reasonable to believe
these things even though they
cannot be proven. Maybe some argument for God's existence will persuade you that belief in
God is reasonable.
So how can we know that God exists? Instead of looking for undoubtable conclusions, we
weigh evidence and consider alternatives. Which alternative best fits the evidence? We
will choose one alternative or another. There is no neutral ground.
II. Where Can we Find Information about God?
When you get to thinking about it, it seems that there are only two basic sources of
information about God, if such a being exists. They are the following:
- We can infer what might be true about God from what we observe in the universe. We
look at the physical universe, human nature and culture and we observe things which may be
clues to the existence or nature of the supernatural.
- God may have entered the Universe and told us true things about himself, morality,
meaning and how to have a relationship with him. This is called Revelation.
Let me explain each of these. One year my wife and I drove from Los Angeles to Rhode
Island. It took a long time. The country is pretty big. From this observation it makes
sense to think that if there is some person or being who is responsible for making the
physical universe, this being has a lot more power than we do. Now this is a rather
simplistic example. Another observation we can make is that every culture we know anything
about has a deep sense that certain things are morally permissible and certain things are
morally prohibited. This leads us to infer that if there is some supernatural being
responsible for human nature, that being is personal. He has a moral aspect to his nature.
The second source of information is that God may have taken the initiative and stepped
into the universe to reveal himself. He may tell us true things about his nature and
purposes and about human meaning and morality.
Christianity holds that both of these are good sources of information. We have clues to
God's existence which can be observed and God has entered the physical universe through
the life and teaching of Jesus of Nazareth in History and told us about himself.
Now in this article I am concentrating on the first source. Can we know anything about God
from what we observe? Are there good reasons to believe in God based on these
observations? I think there are.
III. Reasons to Believe in God
I want to pick up two observations which I think give us good reason to think there is a
God. First, the existence of the universe is better explained by the existence of God.
Second, the existence of objective moral values is better explained by the existence of
A. The Existence of the Universe is Better Explained by The Existence of God.
I will begin by laying out the argument:
- 1. There are things which come into existence.
- Everything which comes into existence is caused to exist by something else.
- There cannot be an infinite series of past causes.
- Therefore, there exists a first cause which did not come into existence.
In other words, the first cause always existed.
Let us look at each of the steps in the argument:
Premise 1. "There are things which come into existence."
Many things have come into existence. This article is coming into existence as I write it.
You came into existence and so did I. This premise is not uncontroversial.
Premise 2. "Everything which comes into existence is caused to exist by something else."
It is obvious that Nothing can cause itself to come into existence. Anything that causes
itself to come into existence has to exist before it exists. This is impossible. Perhaps
something can come into existence from Nothing without any cause whatsoever. Can a thing
just pop into existence with absolutely no cause? This also does not seem reasonable.
I have three children. If I walk into the dining room and see a picture of Pinky and the
Brain which is drawn on the wall in Permanent Magic Marker I will ask "Where did this
picture come from?" My daughter Elizabeth (who is almost five) might say "It came from
nothing, Dad. Nothing caused it. It just popped there. I think it is quite strange -- don't
you?" Will I accept this? No! Things do not come into existence from Nothing without
cause. So, we have good reason to think that premise two is true. Everything which comes
into existence is caused to exist by something else.
Premise 3. "There cannot be an infinite series of past causes."
Is the series of past causes infinite? Can the universe have an infinite past? The answer
is that it cannot. First, there are philosophical reasons to think the past cannot be
infinite. Second, there are scientific reasons which support this view.
Why can't the past be infinite? The answer is that it is impossible to complete an
infinite series by addition. The series of past events is complete. Think of this
mathematical fact. Why is it impossible to count to infinity? It is impossible because, no
matter how long you count, you will always be at a finite number. It is impossible to
complete an actual infinite by successive addition.
The past is complete. This claim means that the entire series of past events ends now. It
ends today. Tomorrow is not part of the series of past events. The series of past events
does not extend into the future. It is complete at the present. If it is impossible to
complete an infinite series by successive addition (as it is impossible to count to
infinity) the past cannot be infinite. If the past is finite., that is, if it had a
beginning, then the universe had a beginning. We have strong philosophical reason to
reject the claim that the universe has always existed.
I will not develop these. Rather, I will simply point them out.
- Big Bang theory does not prove that the universe had a beginning, but it supports
- The second law of thermodynamics does not prove that the universe had a beginning
but it also supports this claim.
We can see that we have good philosophical and Scientific reasons to reject the idea that
the Universe has always existed.
About the Universe, there are only three alternatives:
- 1. The universe has always existed. It has an infinite past.
- The universe was popped into existence from nothing with absolutely no
- The universe was caused to exist by something outside it.
We have strong reason to reject the first two alternatives.
Alternative Three is the most reasonable. There was a first cause. This cause existed
eternally. It initiated the big bang and created the universe. Now what can we know about
this cause? Why think the cause is God? I will briefly sketch a few implications.
First, the first cause is not a part of the space-time physical universe because it caused
the space time universe to begin. Therefore it is outside of space and time. It is not
physical. Second, it has a great deal of power. Third, it is a personal agent. This means
it is not an inert force but it must have aspects of person hood; namely, that it wills.
How do we know this? This is because it is the best answer to the question of why the Big
Bang happened when it did. Why not sooner? Why not later? All of the conditions for
producing the Big Bang existed from eternity. The only kind of cause we know of that can
initiate an effect when all of the conditions are already present is the will of a
I have not argued that it is logically impossible that the universe popped into existence
from nothing without cause. I have argued that it is more reasonable to hold that it has a
cause and that this cause is a non-physical personal agent -- God.
So it seems that the first argument is fairly strong. The existence of the universe is
better explained by the existence of God.
B. The Existence of Objective Moral Values is Better Explained by the Existence of God.
People experience a sense of morality that leads them to hold strongly that certain things
are right or wrong for all people in all cultures. For example, it is wrong to torture
another person just for fun. It is wrong for me today. It is wrong for a citizen of the
Philippines and it was wrong for someone living in 500 BC. Our moral sense provides strong
reason to believe in a personal God.
It will help clarify what I am saying if we put it into the form of an argument.
- If there is no God, there are no objective moral values.
- There are moral values which are objective.
- Therefore, God exists.
Before I discuss this argument, I must make it clear that I am not claiming
that one must believe in God in order to be moral. I am not claiming that statistically
those who believe in God are more moral than those who do not. I am also not
claiming that our knowledge of morality depends upon God. This argument is to
the effect that objective moral values themselves are foreign to a universe
without God. They do not fit.
Defending Premise 1. "If there is no God, there are no objective moral values."
I have to admit that this claim is quite controversial and many philosophers disagree with
me. I think, however, that objective moral values are not sufficiently explained in a
universe without God. Many have agreed with this claim. For example, Dostoevski had Ivan
Karamazov claim, "If there is no God, everything is permitted." Sartre wrote of
Dostoevski's statement, "That is the very starting point of existentialism. Indeed,
everything is permissible if God does not exist, and as a result man is forlorn, because
neither within him nor without does he find anything to cling to." [see his essay
Existentialism] John Mackie -- probably the best philosophical atheist of the twentieth
century recognizes this: "[Objective moral values] constitute so odd a cluster of
qualities and relations that they are most unlikely to have arisen in the ordinary course
of events, without an all-powerful god to create them. If, then, there are such
intrinsically prescriptive objective values, they make the existence of a god more
probable than it would have been without them [The Miracle of Theism, pp 115-116.]
Mackie recognizes that these objective values do not fit in the universe if there is no
God. His answer, since he rejects God, is to claim that there are no objective moral
values. His book on ethics is appropriately titled Ethics: Inventing Right and Wrong. I
agree with Dostoevski, Sartre and Mackie. If there is no God, there are no objective moral
Defending Premise 2. "There are objective moral values."
We know there are objective moral values. By this I mean that the content of morality is
not determined by the individual, or by culture. Rather some things are objectively wrong.
Other things are objectively obligatory. Actions such as rape, racist discrimination and
torturing an innocent baby to death for no reason are really wrong. Furthermore, It is
wrong for me to do these no matter when I live and no matter from what culture I come.
Now many people believe that morality is not objective. This view comes in three basic
1. The individual determines morality.
If the individual determines morality, then if I believe it is morally permissible to
steal your stereo and beat up your girlfriend, it is permissible for me to do it. But it
is not permissible for me to beat up your girlfriend. Therefore, the individual does not
2. Society determines morality.
If I lived in a completely racist society, would racism be right for me? Not at all. When
an American university student protests against South Africa's policy of apartheid, he is
assuming that morality is not determined by society. It is transcendent of cultures. All
of our greatest heroes have been men and women who have stood up to society's wrongs and
appealed to a morality that is transcendent to society in order to demand change. If
society determines morality, it is always morally wrong to criticize society. There is no
morality outside of society which can form the basis of a moral critique.
3. Morality has survival value.
Some people claim that the reason we have this moral sense is that it helped the human
race survive. Those individuals with moral sense grouped together for mutual protection
and these did better than those without the moral sense. This is a kind of prehistoric
social contract theory of morality. The problem with this is that we do not need morality
to survive today. In fact, if you and I know that morality has no objective validity and
the rest of our culture still thinks it is valid, we can take advantage of this to get the
most we can. There is no moral reason to refrain from rape, robbery and murder.
These inadequate objections show that our sense is that there is a morality that is
trans-personal, trans-cultural and trans-temporal The existence of a personal God is the
best explanation for this. It is not up to the individual or the culture whether it is
permissible to rape simply for fun. Any individual who believes it is morally permissible
to rape for fun has a false belief. Any culture whose moral guidelines include the claim
that it is permissible to rape for fun has simply got it wrong.
If it is true that Hitler was morally wrong, it is true that there are objective moral
truths which are trans-cultural. If it is true that it was wrong for Romans to leave baby
girls to die on the trash heaps -- simply because they were girls, then morality is not
determined by culture. If it is true that Martin Luther King was a moral hero because he
criticized his own culture by appealing to objective morality, then it is true that
morality is not determined by culture.
Now, It is true that Hitler was wrong. It is true that the Romans were wrong. It is true
that Martin Luther King was right -- heroically right. So, we know there are objective moral
truths. But objective morality makes no sense in the Universe if there is no God.
Objective moral values point to the existence of a moral being who created the universe.
His moral character is the standard for objective right and wrong.
I have briefly presented two arguments for the existence of God. These show that it is
more reasonable to believe that God exists than that He does not exist.
A. The Existence of the Universe is Better Explained by The Existence of God.
B. The Existence of Objective Moral Values is Better Explained by the Existence of God.
So we see that some of the things we observe about the natural world ground a strong
inference to the claim that God does exist. This gives us reason to consider with renewed
openness the possibility that God has entered the space-time universe and revealed Himself
through the person and life and death of Jesus of Nazareth.
I have not claimed to prove with mathematical certainty that God exists. I have, however,
provided good reasons to think that He does. If someone wishes to argue successfully that
God does not exist. He must first, provide an answer for each of my arguments and second,
he must offer arguments that God does not exist. Until He does this, we can conclude that
we have good reason to claim that God does exist.
Greg Ganssle holds an MA from the University of Rhode Island and a Ph.D. from Syracuse
University, both in Philosophy. He is a faculty member of the Rivendell Center for Christian
Thought, adjunct professor of Philosophy at the International School of Theology and
has been a teaching fellow at Yale University. Greg has served on staff with Campus
Crusade for Christ since 1978. He has published several papers in the areas of
Philosophy of Religion and Metaphysics and is editing a book for Oxford University Press.