mm: John Lennon said, 'God is a concept, by which we measure our pain'. Well, he was about right, because God really is just a concept. See, if there is a real God, and let's grant that IF for now, whatever answer I give you would just be a desciption of God, and as such God---the description---would only be my opinion of God. It ain't the real thing. So, no one can tell you what God is.
What is the color red to a congenital blind person?
To clarify a bit more, for example, the word "apple" refers to something we know, if we have seen, tasted, touched, etc. an apple. But the word "God" refers to something that we don't have a common reference point. Whatever that "thing" you use the word "God" to refer to, isn't here, not in my reality anyway; I don't about yours, though.