I love the Ingersoll quote, Still. His words are poetry, and convey so much better than what I tried to say about man not being able to think up something outside his reality, experience, sight, knowledge.
But to have this seeking for the spiritual... this conception of the spiritual... from a purely physical species?
I am pleased to hear that you enjoyed the quote tec. However, I struggle to see how you can think it supports what you are saying about spiritual things.
You appear to be contradicting yourself. In one breath saying that we are unable to think of anything outside of nature, 'therefore' spiritual things must exist for us to think of them....and that we are unable to imagine/create the idea because we are physical and know only the physical......but we can see that the god concept fits well within human nature.
I fail to see your logic, when everything in the spiritual is just an extension of the physical, mans mind and imagination. It is not a new concept. It is not seperate from our thinking. You seem to disqualify man from being 'spirtual' in a sense. Spirit of course being his energy, emotions and desires. These are not different from the created god that we worship. He is a reflection of our needs and desires.
If we are capable of creating the idea of aliens because of our desire and the world around us....what makes god or spirits so different? We know that our world exists, we know we are not the only galaxy, we know how small we are in the universe and that there is a possibility that life might exist somewhere else....logical.
We have emotions, we have dreams, we love, we feel pain, and we were unable to explain the world in a physical sense. So it would be a logical step for mankind to attribute all these qualities and emotions to a protector, a father figure, a way to explain natural events with human concepts.
A fear of death....would naturally lead to creating an afterlife. The hope of things to come and that life does not end. The thought that maybe we came from somewhere...so where will we be going? Human questions need human answers...'God' answers all these questions. And as the god concept evolves more and more qualities are attributed to him. Perfectly human in every way.
For myself, the more I look at logic and reason, the less I believe in a god. But, I still have a remnant of belief. In what, I no longer know. So I have to come to the conclusion that belief is simply emotion that needs no evidence to support it.