It seems to me we can best say what God is not and leave it at that which will leave that which God is but cannot be said remaining. Although God can not be proven in the physical sense alone to someone else, God can be and is subjectively experienced by being the substrate of existence/Life itself.
If we experience God as an integral part of us then we can say that we are not separate as some theologies would tell us. The questions of, Is there a God?; Where is God?; and What does God look like?; become in a sense, absurd. If God is not separate and the creator and maintainer of all things then we can say that God is in and through all things without exception and God is both invisible as in formless and visible in that God is seen in the things that are made of creation. In the world of duality a paradox is reached making God both immanent and seen as transcendent.
In essence God is without form yet is in all form. God then and creation to me are one and the same. Where does this leave us in our God Concept other than saying God is All in All. It leaves us without a concept.
Nor is there an accurate conceptual view that to me is possible of God to be seen with the mind. Why? Because the essence is beyond the reach of that which is created. A thing cannot see beyond its function. Just as the ear takes in sound but cannot comprehend its hearing, it is beyond the reach of the ear, and the eye takes in light on a field of darkness yet is incapable of ‘seeing’ because it is beyond the capability of the eye. It is the mind that puts these together and presents these things into names and images of forms that can be ‘seen’ or discerned. Now the mind which is a thing of creation can put these and the other 3 sense organs together to create a world but who is it that sees these things and how?
This duality of sight and seen (subject and object) exists only because it is supported by the One. When one searches deeply inward to find who or what it is that is aware of this world as seen by the mind, a barrier is reached, the mind stops, all forms and concepts fall away and one realizes ones true relationship to that world. This One which is beyond concepts cannot be named or conceptualized but is experienced as profound peace and completeness and a sense of home.