Unlike most here, I take the issue of qualia (the subjective experience of what things are like) as quite mysterious. There's nothing I know about matter that would allow me to see red light as the experience of "redness." I take as one possibility either that the Universe is actually idealistic, with all the physical reality really being our experience of a conglomeration of ideas (something like the Matrix), or that the Universe is panpsychic-- i.e. that at least the elements of mind are in everything, or at least in every energetic interchange.
In either of those cases, you could DEFINE God as the sum total of the mental activity of the universe. But the problem with Christians who make this kind of philosophical argument is that it's a pivot point. They'll generally say something like: "Panpsychism, therefore God, therefore believe in Sky Daddy and the resurrection of Christ." This is a sad non sequitur at best.
In either of those cases, you could DEFINE God as the sum total of the mental activity of the universe. But the problem with Christians who make this kind of philosophical argument is that it's a pivot point. They'll generally say something like: "Panpsychism, therefore God, therefore believe in Sky Daddy and the resurrection of Christ." This is a sad non sequitur at best.