Those who believe the Bible know that proof of God is an impossibility in this world. It is faith, not proof, that God requires of us. If God wanted to provide us "proof" of his existence, He would have not made us in His image; He would not have given us free will which is why this forum exists, as well as all the endeavors of mankind.
That typed, we do in fact have proof of the spiritual foundations of ourselves and existence. In addition to the scriptures that proclaim it, so too does science and our very own individual experience of every moment of every day. It is in the findings of Quantum Mechanics and our very ability to interact with the world around us. While this in no way proves the existence of God, it does in fact prove we are spiritual by nature rather then physical.
The Biblical versus that best describe this come from the New Testament. There are other versus in both the Old and New Testaments that do this also, but none better then Romans 1:20, 4:17, 2 Corinthians 4:18, and Hebrews 11:1 & 3. For believers, these versus tell us that God creates what we physically experience from what is not physical, that reality is called into being as though it really exists even while it doesn't physically.
Faith enables us, believer and non believer to experience it as real by the measure of faith God bestows on everyone.
Romans 1:20 states, "For since the Creation of the world His invisible attributes are clearly seen". God's invisible attributes appear to us as physical reality. Romans 4:17 states "God, who gives life to the dead and calls those things which do not exist as though they did". Again, physical experience does not exist, but God makes it seem real.
2 Corinthians 4:18, "For the things which are seen are temporary, but the things which are not seen are eternal". The physical experience is temporary, they are an illusion, while the spiritual reality is eternal. Hebrews 11 1&3, "Now faith is the substance of things hoped for, the evidence of things not seen". "By faith we understand that the worlds were framed by the word of God, so that the things which are seen were not made of things which are visible". Faith allows us to experience as physical things that have no evidence of being physical. It is God's word that creates the experience we know as physically real, but which actually consist exclusively of God's word; his thoughts and consciousness. If you object to how I have defined these verses, please feel free to substitute your own definitions. The results will be the same.
For the non believer this has to of course sound like psycho babble and mumbo jumbo, for how could ancient fisherman, sheep herders, farmers, and the like be discussing the illusions of physical reality? Why would God even bring it up to people who's ability to comprehend such concepts based on the educational levels of the day limit them to understand Quantum level reality and sensory transduction? Because the Bible speaks to all people of all generations. What may not have been understood at one point might be at another. Case in point, the physiology of how we experience physical reality.
The only contact we have with physical experience is in this present moment. Your own sensory processes prove this to you, and you do not need to be a rocket scientist to experience this proof. While the different five physical senses each tell us something different about reality, they function the same way. Scientifically, we have discovered that our bodies are equipped with millions of nerve endings each "detecting" experience. These allow us to "know" what we are looking at, what we hear, smell, taste, and touch.
The process of sensing experience occurs when we detect an outside influence. For example, when light reflects off an object and enters our eyes, the image that light brings gets converted into and electro chemical code by the rods and cones in our eyes, and then sends this code to the area of the brain assigned to visual experience. Here that code is matched against countless other vision codes, and when a match is made, we have the experience of sight. It is at this moment we recognize and define what we are seeing. The same process occurs with our other four senses, but based on different stimuli. Instead of light it might be heat or cold, texture, or pressure, or gas molecules, or molecules in liquid or solid form, or the compression of air. All these allow us to recognize and identify what we see, hear, touch, smell, and taste. While there is still a lot to learn regarding the total function of our senses and recognition's through them, the above is established scientific fact as to how we experience physical reality. Take away these senses, and we are either dead, sleeping, or possibly in a coma.
Understanding this, where does our experience with physical reality happen? If we have no experience of sight, sound, smell, flavor, or touch until our brain recognizes and defines electro chemically coded signals, then the only "place" experience can happen is in our brain, and only at the moment of recognition and definition. Everything we know as physical actually only occurs in the thoughts our brain generates about what is outside us. Even our very physical identity cannot be experienced as physical until recognition of ourselves goes through this same elctro chemical code/decode/recognition/definition process. While this may sound as "spooky" as the above Biblical Scriptures, it is scientific fact. Certainly we also have subjective experience which could be about things physical or of just pure thought, but even these cannot be recognized and defined by us unless we "first" experience our physical identity subjectively. We cannot have any kind of experience without "seeing" ourselves as part of that experience. Certainly there is a lot of denial about this concept because it seems so "unreal", but you need only follow your experiences of your physical senses and the experiences of your thoughts to realize that no matter how unreal this means of experience is, it is in fact our reality. While we are so convinced we have objective experience about stuff all around us, the truth is all of our experience is actually and totally subjective. It occurs in our brain and only at the moment of recognition. We can't hear, see, touch, smell. or taste something experienced at ant time but the moment it was recognized. You can remember it, or imagine it, but you can't experience it as real except right now. Now, how is this even possible to begin with? How can we have been so blind to something so obvious, yet completely opposite to what we think is real physical reality?
Quantum Mechanics is the Science of understanding the most fundamental aspects of existence. If we want to know how things work, why they behave as they do, and how they interact with all other aspects of physical existence, we look to Quantum Mechanics.
Here is where the very nature of atoms and subatomic particles; all the things from which the physical universe and everything in it is made of, including us, begins. If you thought the Biblical Scriptures and nature of our experience above is absurd, this will really blow your mind.
Quantum Mechanics began in the early 1900's with a Physicist named Max Planck with his Planck's Constant formula and more or less took final form in the mid 1920's with Physicists like Heisenberg, Schrodinger, Bohr, de Broglie, Einstein, and other Scientific greats. From then until now, the emphasis has primarily been to disprove it, or come up with a better theory. To date, not only has the original findings of Quantum Mechanics not been disproved, it has instead been repeatedly confirmed and perpetuated. Not withstanding the more recent theories about "String Theory", the "Many Worlds Theory" and the potential discovery of the Higgs Boson, Quantum Mechanics is founded on a few fundamental principles. Among these are Uncertainty, Wave Function, Complimentarity, Decoherence, Entanglement, Non Locality, and others. What Quantum Mechanics describes is a Universe that does not exist until it is "observed", that there is no cause and effect in the Quantum experience, just an instantaneous now from which one of an infinite number of probabilities materializes as physical experience only when observed or measured, and that all quantum states are aware of and have communication with each other, again, instantaneously. Obviously this is as far removed from the experience we each know as is possible to get, yet these, among other as bazaar findings, are the results obtained over the last 100 plus years of investigating, experimenting, and attempts to disprove what is the foundation of our physical reality.
Naturally, there are many who will dispute this because it so obviously conforms to the actual subjective experience we have and the Biblical descriptions of reality above. Denial however does not change the facts, and again, even for non believers, you have the direct evidence of your non physical foundational being in the way you experience all you do, as subjective experience exclusively.
Does any of this prove the existence of God? Of course not, nor can it. That is a matter of faith, the exact same faith that allows you to see things as physical when they are not physical in the first place. WE each are spiritual and we each are our proof of it.
At least I hope this gives a different perspective on this forum's topic.
Cheers