This post arises from my last, which was an argument for the existence of God from the impossibility of absolute nothingness. The hinge of the argument, its fulcrum, was in this paragraph:
To say [that, it being impossible that there should be no state of affairs whatever, so then some state of affairs must be necessary] is to say only, and exactly, that God is necessary. For, there are innumerable states of affairs in which this or that comes to pass contingently, but not necessarily. All those contingent passages and states of affairs are, by definition, not necessary. … But there is and must be a basic state of affairs that is necessary, and *not contingent;* in no other way could it be possible for other states of affairs to continge.
The idea is that, absolute nothingness being an incoherent concept, thus ontologically impossible, there must necessarily be some state of affairs; but that any contingent state of affairs, being not itself necessary, cannot be among the states of affairs that must necessarily be; so that, the mere fact that there must necessarily be some state of affairs entails that there must be a state of affairs that is in itself necessary.
That necessary state of affairs is what all men have always called God. It is the basic state of affairs, upon which all other states of affairs continge. Thus the QED with which I finished the post.
OK: what’s the absolution of being mentioned in the title of this post?
It is simply the simplicity of being per se, prior to any specification of any particular, thus contingent actual state of affairs. It is the necessary possibility of some and then of any particular state of affairs, and so of every possible state of affairs. It is the forecondition of all specific, thus contingent being. Being per se must be necessarily if there is then to be any particular state of affairs.
Necessary state of affairs → contingent state of affairs; contingent state of affairs; ergo, necessary state of affairs.
Excursus: I do not here venture any argument that there can be only one necessary state of affairs: only one eternal, only one perfect, only one simple, and so forth. Others have done so, and so have I. Right now I don’t have the moral bandwidth, the mere physiological bandwidth, to search for links to such arguments, but they are easy enough to find for those who seek diligently.
Being per se is necessary. But being per se is not any particular being. It is, rather, particular being as such. It is the very possibility of particular being; and, then, so is it the actuality of particular being.
All the foregoing is logically prior to the hierarchy of particular beings, with the Trinity at the top and everything else in goodly order of battle beneath: Sabaoth.
The Orthosphere 
Going into speculation. I heard stories about those who came back from the afterlife. Where the “outer darkness” was simply the black void of nothingness.
Before Creation. It would seem strange that God would inhabit the infinite void without lighting it up. Unless before Creation. All existence is both infinite void and Infinite Being somehow before Finite Creation came into being.
The outer darkness would still not be nothing, for there would be in it the void itself, its darkness, and the patients thereof, together with their feelings, memories, regrets, thoughts, and so forth; and we hear that there will in it be also weeping and gnashing of teeth, and painful apprehensions by its patients of the feast from which they have been ejected as unfit. So, almost but not quite nothing.
There is no such thing as before creation, inasmuch as sequence, causal relations, thus time and space, and so before, after, distance, location, and so forth are all aspects of the created order. Time comes into being with creatures who can be causally and thus temporally related to each other.
Nor is there any void ‒ any space ‒ in which God resides. God is the locus of space, and not vice versa. Acts 17:28.
All that said, your last sentence is I think correct: the particular finite creatures of the created order logically supervene (and so partake, and indeed consist in) Being as such, who is not any particular thing and so is like a void, but who is yet the subsistence of every particular thing. Your last sentence sounds like you have been reading Neo-Platonists, like Augustine.