Theism is just one of seven worldviews. And our culture has people who believe in all of them. As a result, some people think their religion alone is true (exclusivism). In contrast, others believe that all worldviews are equally valid (pluralism).
Theism believes in one eternal God who is infinite in all his attributes. He created everything and is both beyond and within his creation. He performs miracles.
I. But First: What’s A Worldview?
A worldview is how we:
- First, take in the data of life over a broad range of topics
- Second, process that data
- Third, makes decisions from this process
- And finally, act on those decisions.
Each worldview contains beliefs in six different areas. The mnemonic “GO HOME” helps in remembering these six areas:
- Where we came from (Origin)
- What it means to be human (Humanity)
- Morality (Ought)
- Life’s meaning (Meaning)
- Where we are going (End)
II. Theism is One of Seven Worldviews
There are seven worldviews. Each has a different belief in the existence and attributes of God.
- Atheism: no god(s)
- Polytheism: many finite gods
- Finite Godism: a single finite god (who has a limit or end) who is not identified with the world
- Pan-en-theism: a single finite god who is identified with the world
- Pantheism: an infinite god without boundaries or limits. This god is identified with the world
- Deism: an infinite God who is not identified with the world but doesn’t perform miracles
- Theism: an infinite God who is not identified with the world and does perform miracles
III. Two Tests That Prove Theism is the Correct Worldview: Undeniabilty and Unaffirmability
With so many choices, how can we determine which one is the seven worldviews is the correct one?
Fortunately, Dr. Norman Geisler teaches two ways to prove theism is true. In his Christian Apologetics, his two tests are:
- Undeniability: the correct worldview will be “undeniably true”
- Unaffirmability: false worldviews have contradictions and mistakes within their core principles
Let’s consider undeniability first. In the following article, we will deal with unaffirmability.
IV. What Does “Undeniability” Mean?
In brief, undeniability means a statement or proposition is so true you can’t deny it.
And what’s more, if you try to deny it, you contradict yourself.
Are you baffled? Some examples should clear up any confusion and help us on our way to proving theism is the only true worldview.
1. Start with the Undeniable Truth: “I Exist.”
To prove theism is correct, we must start with a point of reference agreeable to everyone.
For example, my saying, “I exist.” This truth is undeniable.
- First, because I am right here stating the obvious
- Second, I cannot deny I exist without contradicting myself.
Why? Because I have to exist to say, “I do not exist.” So in that sense, it is “undeniable” that I live.
And from that simple absolute certainty, we can prove that the theistic God of the Bible must exist.
2. Second Undeniable Truth: Principle of Causality: Talk About Your Parents
Our first undeniable fact is that “I exist.”
The next question is, “Do I have to exist?
- My existence is not necessary. In other words, I don’t have to exist.
If I don’t have to exist, several facts lead to certain undeniable conclusions:
- I was “caused” or “created” to exist by someone else.
- My existence depends on others, namely my parents.
- That means I am dependent or “contingent” on my parents.
- Since my parents created me, I had a beginning. I haven’t existed forever.
- And someday, I will die or go out of existence.
- If I am contingent, I had a beginning and will have an end. Thus, I am “finite” and not infinite.
Every one of those points is undeniable.
The next question is, “If your parents caused you, who or what caused your parents?
The answer is their parents, or your grandparents created them.
And so on backward in a “cause-effect” series. In other words, working backwards, we have each parent (cause) creating their contingent child (effect).
This undeniable law of “cause-and-effect” is known as the Principle of Causality. In brief,
- “Every contingent effect (child) has a cause (parent).”
- Or, more simply, anything that comes into existence (contingency) has a cause.
- This principle is undeniably true.
a. There Cannot Be an Actual Infinite Number of Causes in a Finite Universe.
Now we have reached a critical part of the argument! Could this backward series of “cause-and-effect” go on forever?
To put it differently, could there be an actual or “real” number of infinite “causes?” No!
First, because we live in a “finite” universe, that science has proven to have a beginning. That means it is limited in:
In contrast, an infinite series is limitless. It has no beginning or end. Therefore, such a series can’t exist in our finite universe!
It would be analogous to trying to fit a college football stadium into a snow globe. Except, of course, the stadium would be limitless.
The second reason we can’t go back infinitely is that an infinite series, by definition, has no beginning and no end.
Therefore, an “infinite” is only a theoretical, abstract, or mathematical construct. It cannot actually exist in the real world, where series have real beginnings and ends.
To put it another way, ask if we can ever reach the “first cause” of an infinite series.
The answer is no because, by definition, an infinite series has no beginning or end!
This philosophical mistake (fallacy) is called an “infinite regress.”
- It states that you can’t keep going backward forever.
- For example, atheism and other religions make this mistake. They claim the universe is infinitely old. That is impossible.
So do you see the problem we are facing?
- We are finite, created beings needing some point of origin.
- But if the series attempting to lead us back to our very beginning is infinite, we can never get there.
So how do we resolve this dilemma?
3. Third Undeniable Truth: There Must be a First Uncaused Creator!
The answer to our dilemma is obvious. Our backward-directed string of “cause-and-effects” needs to stop somewhere. It needs to have an actual beginning.
Because as we have shown:
- First, “I exist.”
- Second, I am a contingent “effect” caused by another.
- Third, the cause-effect series cannot go backward forever. A series without a beginning first cause results in an infinite regress?
- Fourth, the series leading to my undeniable existence must have started somewhere.
So there is only one logical answer.
The whole series of causes had to begin with a First Uncaused Creator. Why this specific Being?
- “First,” it is undeniable that I exist now. Thus the series of “cause-and-effect” started at some moment.
- “Uncaused” since there cannot be an infinite regress of causes. There has to be some Being that was not caused by another.
- “Creator” since someone had to create the first person in the series. And my existence ultimately resulted from that first person.
Therefore, there must be a First Uncaused Creator who was not created and is eternal (beyond time).
4. Fourth Undeniable Truth: This is the God of Theism
This First Uncaused Creator is eternal. Therefore, he cannot be either “self-caused” or “caused by another.” But he must have specific characteristics. For example:
- As Creator, he must be beyond all constraints of our finite universe—specifically all time-space, matter, and energy.
- Since he is eternal, he must be unlimited or infinite
- Accordingly, all his attributes are limitless, including being all-powerful, all-knowing, and all-perfect
But these are unquestionably the attributes of a theistic God.
V. Therefore, the Existence of a Theistic God is Undeniably True
Did you follow the argument? The reasoning is flawless. Meaning every statement in the argument is valid and irrefutable.
It is undeniable that a theistic God exists. And this God is identical to the God described in the Christian Scriptures. And he is the ultimate reason for your current existence.
But even though this argument demonstrates the truthfulness of a theistic God, you cannot know how to have a personal relationship with him without the Bible.
Are you considering Christianity’s claims? We hope you discover that this theistic God of Christianity loves you. And he is the same God who sent Jesus and invites us into a personal relationship with him.
Geisler, N. L. (2013). Christian Apologetics 2nd ed. Grand Rapids: Baker Book House.
_________ (2012) The Big Book of Christian Apologetics: An A to Z Guide. Grand Rapids: Baker Book House.
_________ , & Watkins, W. D. (1989). Worlds Apart: A Handbook on World Views (2nd ed.). Grand Rapids, MI: Baker Book House.