Aristotle managed to prove the existence of the First Cause from first principles and reflections on world around him. Thomas Aquinas went further and showed that the First Cause must have Intellect and Will in a manner analogous to human intellect and will (or, rather, vice versa, for the causality runs the other way). But I know of only one way to prove God “with all the trimmings”: that is, to become convinced that God is the God of Abraham, Isaac, and Jacob, that God is Father, Son, and Holy Spirit, that God the Son is also the Man Jesus Christ, and that’s to have an encounter with Him.
And that’s both the easiest thing and the hardest thing in the world.
It’s the easiest thing because it takes almost no set up, and no apparatus. All you need is a few moments of quiet to say, in the quiet of your room, out loud or silently in your head, “God, I don’t know whether you exist or not. If you do, please show yourself to me as you really are.”
It’s the hardest thing in the world because when I say that I have to mean it. I have to be open to the possibility that God might actually exist—because if I’m not open to that possibility, why bother asking the question? There’s no point in conducting the experiment if there’s no possible outcome that could change my mind.
And if God does exist—the almighty creator of the entire cosmology-du-jour—then I am His creation, whether directly or indirectly. He has a claim on me, and might have views about how I ought to live, views I might find extremely unpleasant. Once you open that door, there’s no telling where it might lead.
I don’t claim that God will respond immediately and recognizably. Every person is different, and God meets everyone where they are, in the way that will work best for them in the long run. But if you pray that prayer sincerely, then yes, I do claim that in time it will be answered.
And then you’ll be the one trying to explain to others why you believe this stuff.
image credit: Michelangelo Buonarroti [Public domain], via Wikimedia Commons