How Rational Is It to Ponder God’s Existence?


Do your ever wonder whether God exists? Maybe you are tempted to say it just makes no sense to think that way. Do we really leave logic behind when we mount an argument that points to God’s existence?

Sure, it’s possible to propose an illogical argument involving God. The plot of Star Trek V: The Final Frontier, which suggested God might live in the centre of the galaxy, is a great example! Hey – as a nerd, I think Star Trek The Motion Picture is a much better treatise on faith and the personal spiritual journey.

Leaving Star Trek aside, in this blog, I’m going to argue that it is possible to mount a logical argument for the existence of God. Why? Because:

  1. Humanity has received the Laws of Logic and we use them in our thoughts and disciplines. They aren’t invented by us.
  2. The idea that the universe has a first cause is consistent with the Laws of Logic.
  3. Mounting an argument for God’s existence is not only logical, it leads to the possibility of renewed hope in our personal lives.



FIRST – what do I mean by the Laws of Logic and their impact on humanity?

Traditionally, there are three fundamental laws guiding logical human (and Vulcan) thought.

1 – the Principle of Non-Contradiction.

For all propositions p, it is impossible for both p and not p to be true. In other words, if I believe that I am about to pick up a hamburger, I cannot therefore be about to take a bite out of a flying saucer. It is a hamburger.

2 – the Principle of Excluded Middle.

Either Socrates is mortal, or it is not the case that Socrates is mortal. The middle position, that Socrates is neither mortal or not-mortal, is excluded by the Laws of Logic.

3 – the Principle of Identity.

A thing is identical with itself.

Where do the Laws of Logic come from? Well, that’s a tough question to think about because they are a-priori to human thought. They come before anything that the human mind writes or says. It seems unnecessary to even consider these laws as they seem so basic and obvious to us. They come packaged as part of our finely ordered universe.

What’s more, we don’t actually have the tools to try to work out whether the laws are true and valid, because all our approaches presuppose them. More scientific discoveries won’t help us here. Why?  Bonnette opines, “No one can actually doubt or deny the principle of non-contradiction – for the very act of denying or doubting presupposes its validity. To say, ‘I deny,’ is to affirm that you deny and to deny that you affirm, both of which need the Principle of Non-Contradiction for their very intelligibility.”[1]

So, we have to simply receive these logical laws and apply them if we are going to make any sense as we think and communicate. We didn’t invent them, we naturally connect to them and use them as we reason and interact.


SECOND – a first cause of the universe is completely consistent with the Logical Laws we must appeal to

What do I mean? Well, let’s look at a logical argument for the existence of God as the first cause of the universe, or multi-verse (it’s a similar argument for both). The Kalam Cosmological argument says this:

1 – Everything that BEGINS to exist has a cause.

This is one of those obvious statements. It’s not particularly controversial because it’s based on our everyday experience and scientific understanding of the universe. Things don’t pop into existence unexpectedly in our experience.

2 – The universe began to exist.

We know this from scientific methodologies that validate the theory of the big bang. For example,  the measurement of background radiation in the cosmos and the red shift of the galaxies we observe from earth. Everything is in motion from a single point where space, time and matter came into existence billions of years ago.

3 – Therefore the universe has a cause. 

This follows logically from the first two premises. If they are both true, then this is a logical conclusion.

And – we can go further and suggest some attributes of this first cause. It must be timeless and immaterial. It must itself be uncaused, and incredibly powerful. Also, it must be personal. Why? Because we are conscious beings who live in the universe. That being the case, the first cause must also be conscious. The effect cannot be greater than the cause. Further, it must have taken will and choice to cause the universe. It can’t have been the result of physical cause and effect, because there was no cause and no effect. These notions presuppose physical laws that themselves came into being at the creation of the universe as we know it. No, it is reasonable to assume the universe has a personal cause.

The Kalam is only one of a number of logical arguments that point to the existence of a God. To refute this argument, you have to show that one or either of the premises are invalid, or that the conclusion does not follow from the premises.


THIRD – okay the argument is logical, but so what?

We’ve seen that not only do we receive the Laws of Logic, but they guide our considerations about the idea that God exists as a first cause of the universe. He created everything ex nihilo, from nothing at all. There was nothing … then the big bang … and space-time began. The Laws of Logic don’t tell us much about what this God is like. For that, we have to look elsewhere. But they do get us started in a proper and rational way.

Of course, not everyone is comfortable with the idea that a rational argument can contain the idea of God. If one begins by discounting God altogether, taking the Naturalist philosophical position, then the idea of a God makes no sense because all that exists is found within the bounds of the universe. There is no supernatural, just natural. To the Naturalist, an argument like the Kalam may follow logically, but it probably makes no sense to them based on their presuppositions.

The problem with allowing our presuppositions to dictate our thinking here is – it leaves us with having to settle without an explanation. Our thinking is essentially constrained to the confines of the universe itself, we are therefore unable to consider a cause of it. This seems very unsatisfying.

Even so, scientists have formed naturalistic theories about the creation of the universe that do not require a personal first cause. Unfortunately, they also re-define the “nothing” that the universe must logically have been created from. The late Stephen Hawking, and Leonard Mlodinow, state in their naturalistic model that, “Because there is a law like gravity, the universe can and will create itself from nothing.”[2] But what do they mean by “nothing?” Craig explains. “The nothingness … is not really nothingness after all but is space filled with vacuum energy….’nothing’ in their vocabulary does not have the traditional meaning ‘nonbeing’ but rather means ‘the quantum vacuum’…Hawking and Mlodinow have avoided the tough question by equivocation.”[3]

Yet the Theist has no such problems facing the tough issues around the creation of the universe. The universe appeared from actual nothing, and the cause of its appearing was a first cause whose properties sound very much like the traditional description of God.

How rational is it to ponder God’s existence? Well – it depends on your argument! But – it can be completely rational.


FOURTH – so where’s the hope?

The idea of God isn’t just a logical proposition. It is also a source of much hope and real encouragement to us right now. Why? Well, surely if God willed a finely crafted, logical universe into existence then he had a purpose in doing so? We are alive now, and we are considering these issues together. There must therefore be a purpose in our own personal existence? The universe was created for a purpose, and so were we. There’s a good reason why we are here, and part of the result of getting to know that God, is learning more about the purposes he has for us in his good creation.

If the creation is very good…on what basis must we assume God’s purposes for our lives are any less good?



[1]Dennis Bonnette, The Principle of Non-Contradiction’s Incredible Implications, Strange Notions The Digital Areopagus – Reason, Faith, Dialogue,

[2] Stephen Hawking and Leonard Mlodinow, The Grand Design quoted in The Grand Design Truth or Fiction,

[3] William Lane Craig, The Grand Design Truth or Fiction,


Photo by Tachina Lee on Unsplash