Natural theology is the science of God’s existence, and it’s a massive trove of evidence and reason of the first order.
Through reason we can infer the unseen from the seen — everything from the existence of unseen electrons to the existence of an unseen intelligent designer from the evidence of design in nature.
I can describe anything you like in whatever detail you like, but you can’t know whether it exists or not merely by its description.
The design we infer in nature is an insight we abstract from our senses, but the inference itself is acquired by our reason.
Sir David Attenborough, an agnostic, invokes a rather nice metaphor about a termite mound.