Jehovah God is intrinsic reality because from eternity to eternity he is the I Am, the Absolute, and the first and only thing from which comes everything that exists and to which everything owes its existence. Because of this and nothing else he is the Beginning and the End, the First and the Last, and the Alpha and the Omega.
One cannot say that his underlying reality comes from himself, because coming from himself implies before and after, and therefore time, and time cannot apply to the infinite underlying reality that is described as existing from eternity. Coming from also either implies another god who is the real god, and then you have a god from a god; or it implies that God formed himself. In either case God would not be uncreated or infinite, because he would have boundaries and limitations that were imposed either by himself or by some other god.
From the fact that God is the intrinsic underlying reality, it follows that God is love in itself, wisdom in itself, and life in itself. It also follows that God is the Absolute from which all things come and to which all things are connected so that they may exist. God is God because he is life in itself, as the Lord’s words in John 5:26 make clear. Likewise in Isaiah: “I, Jehovah, am the maker of all things. I alone stretch out the heavens. I extend the earth by myself” (Isaiah 44:24); and he alone is God, and there is no God except him (Isaiah 45:14, 21; see also Hosea 13:4).
God is not only the intrinsic underlying reality but is also an intrinsic capacity to become manifest. For unless the underlying reality is capable of manifesting, it is nothing. It is equally true that the capacity to become manifest is nothing without the underlying reality. Neither one can exist without the other. The same is true for substance unless it takes a form. A substance without a form has no properties or attributes, and something that has no quality is in fact nothing.
I speak specifically here of underlying reality and capacity to become manifest, not of essence and actual manifestation, because the relationship between underlying reality and essence is the relationship between something that comes before and something that comes afterward; the same goes for the capacity to become manifest and actual manifestation. What comes before is more universal than what comes afterward. The underlying divine reality has the attributes of infinity and eternity, but the divine essence and manifestation have the attributes of divine love and divine wisdom, and through them, omnipotence and omnipresence, which I will get to when it is their turn.
from True Christianity, Volume 1, Section 21