Max Muller, the nineteenth century philologist and orientalist, delivered lectures in 1891 on the subject of Anthropological Religion. Obviously these lectures are dated now, but he used the oak tree as a symbol of the history of the human attempt to come to grips with the concept of a higher power. I still find that symbol helpful.
I should go so far as to say that the history of religion is the best proof of religion just as the growth of the oak-tree is the best proof of the oak-tree. There may be excrescences there may be dead leaves there may be broken branches but the oak-tree is there once for all whether in the sacred groves of Germany or at Dodona or in the Himalayan forests. It is there not by our own will but by itself or by a Higher Will. There may be corruptions there may be antiquated formulas there may be sacred writings flung to the wind but religion is there once for all in all its various representations. You can as little sweep away the oak-tree with its millions of seeds from the face of the earth as you can eradicate religion, true religion, from the human heart.
Some think there will be a day when religion will have run its course in the hearts of humans. But I doubt it, just a Muller did.
Our ideas about God have evolved over the millennia and will continue to evolve in the centuries ahead.
I believe God has hardwired into the human mind the impulse to seek him. To quote Muller again:
There will be and can be no rest till we admit, what cannot be denied, that there is in man a third faculty, which I call simply the faculty of apprehending the Infinite, not only in religion, but in all things; a power independent of sense and reason, a power in a certain sense contradicted by sense and reason; but yet, I suppose, a very real power, if we see how it has held its own from the beginning of the world — how neither sense nor reason has been able to overcome it, while it alone is able to overcome both reason and sense.
Yes, the growth of the oak tree is the proof of the oak tree.