God is so quiet

[Angrboda]

Forgive me if I've misunderstood, but from my perusal of this thread I was under the impression that you were using the premise that the universe is contingent in service to your natural theology arguments.  Since the aim of those arguments is to derive the conclusion that God exists, your use of the idea of something god-like, which is by your definition a necessary being, to derive the result that the universe is contingent, is improper.  Doing so would be to invoke the existence of God, to derive the contingency of the universe, to then use that result to derive the conclusion that God exists.  That would be a clear case of begging the question. 

I don't know what you mean by "some other medium of existence" here, but regardless, I'd appreciate it if you'd clarify what greater argument you are using the result of the universe's contingency in service toward. (I'm not sure what you're working toward by invoking additional contingent entities such as an 'other' medium of existence and would appreciate you clarifying exactly what the relationship to the current question is.  In regard to your comments about infinite regresses and occam's razor, I will simply caution you that if such objections are in the service of supporting natural theology arguments of the usual sort, I consider such objections problematic for reasons we will get into if the conversation turns in that direction.)

The hurdle in the discussion was proving that the cosmos is a contingent entity. There were several who thought it was not contingent.  

I tried to show this using the conception of a possible world that had 'nothing' in it. That brings up other problems about what 'nothing' is. I realized my mistake and changed my point to say there is a possible world where there is something else besides our cosmos. This possible world could consist of just God (or something akin to God), perhaps just minds, perhaps some other substance (I used the word medium) that contained other entities. It really doesn't matter what the example is because the the point I was trying to prove is the very conservative claim: our cosmos is contingent. 

The conversation really had not gotten to any objections about God being the first cause yet  because of near constant pressing the issue on whether the cosmos was a necessary entity or not. Are you willing to grant that the cosmos seems to be a contingent entity?

Here is my take on the question you are proposing. You want to arrive at the result that the universe is contingent. There are multiple paths toward that end, and I think it would be instructive to examine some of them. The first such path is to argue that the universe is contingent by way of analogy with objects existing within the universe. Unfortunately that path is open to numerous objections which render it of little use in greater arguments. So I think that is all that needs to be said about that.

Another path is to assume that the universe is necessary, and then in a reductio ad absurdum demonstrate that this leads to a contradiction, either logically or a contradiction with known properties of the universe (e.g. Craig's attempt to show that there was a "time" when the universe did not exist via the Borde-Guth-Vilenkin theorem). This approach has both advantages and disadvantages, but since this doesn't appear to be the path you've taken, I will simply leave it at that.

A third path is to simply assume the universe is contingent without justification. As a matter of definition, it is the very meaning of the term contingent that the entity in question does not exist in all possible worlds. When people argue ala possible worlds with respect to God, they typically assume as a matter of definition that God is necessary unless doing so results in a contradiction. If one applies the same principle to the universe, there does not appear to be any inherent contradiction with assuming that the universe is necessary, if one is going solely by the arguments about possible worlds you've presented here. Rather than having demonstrated that the universe is contingent, you've simply expressed the proposition that the universe is contingent using the semantics of possible worlds. You assume the universe is contingent, to derive the result that the universe doesn't necessarily exist in all possible worlds, to turn around and use that as justification that the universe is contingent. But "not necessarily existing in all possible worlds" is the definition of contingency, so to all appearances, you have simply assumed that the universe is contingent, then used a discussion of possible worlds to camouflage that assumption.

If indeed you are simply assuming the contingency of the universe without justification, as I've suggested here, I have no problem entertaining the notion ex hypothesi as in, "if the universe is contingent, then X, Y, and Z follows," however given the arguments I suspect you are likely to make, such a move won't profitably suit your ends. If one simply wishes to assert the proposition that the universe is contingent without justification, as I believe you have done, then that opens one's argument to the simple expedient of simply rejecting your assumption, equally without justification. Regardless, if I'm correct here, your detour into the field of possible worlds does not substantively advance your claim that the universe is contingent, so any argument based upon the proposition will have to depend upon other arguments than this possible worlds business.