I will never buy that Chuck is/was God, unless they come out and say it. I'm not one that buys into that theory.
I do not think we've seen God in the show yet, IMO.
You're certainly free to think what you want, but when the show all but says it and
it's backed up not only by the actor *and* the showrunner's comments, well, to each their own.
But God's been on the show, whether you want to believe it or not.