November 30, 2025
How Do We Know God Exists?
Recently I was listening to a religious talk show on the radio when a caller asked: How do we know that God exists? A good question.
The radio host answered by saying that we know it through faith. That’s not a bad answer, except what needs to be teased out is how we know this through faith.
First, what does it mean to know something? If we believe that to know something means to be able to somehow picture it, understand it, and imagine its existence, then this side of eternity, we can never know God. Why?
Because God is ineffable. That’s the first and non-negotiable truth we need to accept about God and it means that God, by definition, is beyond our imagination. God is infinite and the infinite can never be circumscribed or captured in a concept. Try imagining the highest number to which it is possible to count. God’s nature and existence can never be conceptualized or imagined. But it can be known.
Knowing isn’t always in the head, something we can explicate, own in a picture, and give words to. Sometimes, particularly with things touching the deepest mysteries in life, we know beyond our head and our heart. This knowing is in our gut, something felt as a moral imperative, a nudge, a call, an obligation, a voice which tells us what we must do to stay true. It’s there we know God, beyond any imaginative, intellectual, or even affective grasp.
The revealed truths about God in scripture, in Christian tradition, and in the witness of the lives of martyrs and saints, simply give expression to something we already know, as the mystics put it, in a dark way.
So, how might we prove the existence of God?
I wrote my doctoral thesis on exactly that question. In that thesis, I take up the classical proofs for the existence of God as we see these articulated in Western philosophy. For example, Thomas Aquinas tried to prove God’s existence in five separate arguments.
Here’s one of those arguments: Imagine walking down a road and seeing a stone and asking yourself, how did it get there? Given the brute reality of a stone, you can simply answer, it’s always been there. However, imagine walking down a road and seeing a clock still keeping time. Can you still say, it’s always been there? No, it can’t always have been there because it has an intelligent design that someone must have built into it and it is ticking away the hours, which means it cannot have been there forever.
Aquinas then asks us to apply this to our own existence and to the universe. Creation has an incredibly intelligent design and, as we know from contemporary physics, has not always existed. Something or someone with intelligence has given us and the universe a historical beginning and an intelligent design. Who?
How much weight does an argument like this carry? There was once a famous debate on BBC radio in England between Frederick Copleston, a renowned Christian philosopher, and Bertrand Russell, a brilliant agnostic thinker. After all the give and take in their debate, they agreed, as atheist and believer, on this one thing: If the world makes sense then God exists. As an atheist, Russell agreed to that, but then went on to say that ultimately the world doesn’t make sense.
Most thinking atheists accept that the world doesn’t’ make sense; but then, like Albert Camus, struggle with the question, how can it not make sense? If there isn’t a God then how can we say that is better to help a child than to abuse a child? If there isn’t a God, how can we ground rationality and morality?
At the end of my thesis, I concluded that existence of God cannot be proven through a rational argument, a logical syllogism, or a mathematical equation, albeit all of those can give some compelling hints regarding God’s existence.
However, God is not found at the end of an argument, a syllogism, or an equation. God’s existence, life, and love are known (they are experienced) inside a certain way of living.
Simply put, if we live in a certain way, in the way all religions worthy of the name (not least Christianity) invite us to live, namely, with compassion, selflessness, forgiveness, generosity, patience, long-suffering, fidelity, and gratitude, then we will know God’s existence by participation in God’s very life – and whether or not we have an imaginative sense of God’s existence is of no importance.
Why do I believe in God? Not because I’m particularly persuaded by proofs from great philosophical minds like Aquinas, Anselm, Descartes, Leibnitz, or Hartshorne. I find their proofs intellectually intriguing but existentially less persuasive.
I believe in God because I sense God’s presence at a gut level, as a silent voice, as a call, an invitation, a moral imperative which, whenever listened to and obeyed, brings community, love, peace, and purpose.
That’s the real proof for the existence of God.
Oblate Father Ron Rolheiser is a theologian, teacher, and award-winning author.
He can be contacted through his website www.ronrolheiser.com.
Follow on Facebook www.facebook.com/ronrolheiser