Edit: I got my math symbol backwards... I think.
Could there be anything greater than or equal to God?
Could anything exist apart from him?
Could there be a reality outside of God?... That he exists within?
If so, would this reality be considered greater than him since it contains him?
It can help to understand presumptions of course. Consider this key one --
Naturalism: "a philosophical viewpoint according to which everything arises from natural properties and causes, and supernatural or spiritual explanations are excluded..."
In other words, the assumption that God would have to be contained inside nature.
That God is inside/subject to physics. An assumption.
Of course, few people that presume naturalism even become aware of it as being an assumption or premise.
Obviously, if you presume naturalism then God is less than the totality of nature, then merely a part of the Universe, contained inside of it.
But the assumption contradicts what believers typically know about God, that He literally originated nature as we see it, all the Universe.
Now, the Universe is simply physics. (The Universe is merely physics in action) A person with a degree in physics that believes in God could say, like me, that God created physics (chose, fine tuned, built...or simply spoke it into being). He is above physics. Independent of physics.
But I don't think of God as merely outside or above the Universe, but instead,
He is unknowable in totality, and we only sense Him in part, at most, and He is the ground of being, of existence itself. That something exists, instead of nothing.
If these words communicate something, that's great. But if not, they are merely words, yes? See? The transcendent isn't capturable by words ultimately.
Campbell helped point at this. To paraphrase, poor descriptions attempt to specify that which cannot be specified. A better description tries to suggest the ineffable. The best description (which mine here isn't) could help point towards the ineffable. Such as many of the Psalms, for instance. But, as Campbell said, even that is inadequate to capture the ineffable. At best, it helps us to connect to our own connection. If we are willing to find that. It's a seeking process.
13 "You will seek me and find me when you seek me with all your heart."