My experience of these kinds of models is that there are two basic options for God.
* God can be the "ground of being," the source of existence (in the Hindu pantheon this = Brahman).
* Or God can be an organising principle that causes material existence to manifest as it does and that operates within this "ground of being," (in the Hindu pantheon this = Ishwara).
Thus the Christian God is essentially the latter, and analogous to the Hindu Ishwara.
This is why the Christian God is in particular trouble when confronted with Darwinism. Previously it seemed to people that there must be some form of organising principle in the universe, some blueprint or pattern behind the scenes which caused things to develop the way they did. Universal Darwinism puts paid to this within the kingdoms of nature. And mathematics starts to deal with God in the mineral world.
God as Brahman, the "ground of being", is of course ineffable, for anything one might care to say about it is merely another emanation from it. It cannot be described for it has by definition no attributes. BTW, these two notions of God were reconciled somewhat in later Vedantic schools like Advaita, see Shankara and others.
Nick