a first class clown . . . full of crap . . . crop of mutts . . . . enemies of God himself . . . . produces nothing but gibberish

Brilliant critique!

These types of people are actually not "Thinkers" at all. Carroll and this other current crop of mutts have set themselves up as enemies of God himself .. and that produces nothing but gibberish

You should visit that site to see evidence:
http://turkishatheist.net/?p=1

The answer lies within your question - "necessary".

Necessary in the sense that in order to account for a reality that is purely contingent (i.e. isn't self-explanatory, constantly changes, and is not eternally-existent), one must recognise the reality of something (it need not be the traditional concept of God, by the way) that both accounts for and transcends it. Physical reality is not a "brute fact", because, among other things, it has not always existed. The concept of reality being cyclic in nature just shifts the problem up one level, for one has to then account for the entire ensemble of 'universes'. The multiverse idea suffers from the same deficiency.

Yes, my answer is a month late, but... what the hell. :)

But apparently, this open-minded prescription only applies to religious believers, and not poetic naturalists like Carroll, since as noted above, he twice admits to being "unequivocally" certain (i.e., without any doubt) that the universe could exist all by itself.

But this is based on your own misreadingl. You owe Carrol an apology. Here is the part you quote and misread:

He writes, "The progress of modern physics and cosmology has sent a fairly unequivocal message: there's nothing wrong with the universe existing without any external help" (196). A few pages later he writes, "To the question of whether the universe could possibly exist all by itself, without any external help, science offers an unequivocal answer: sure it could" (201).

You may think Carrol is not qualified to make such confident statements about the Universe, but you must at least grant him the right to make unequivocal statements about Physics. For that is all he is doing here.

When he says "there's nothing wrong with the universe existing without any help," he is stating that this does not violate any physics. He is saying physics has not proven this cannot be, nor does it contradict any known theory of physics. He's not saying it must be true that the universe exists without any help.

Likewise, when he asks if the universe "could possibly exist all by itself", he is again saying that IF the answer were yes, it would not contradict scientific knowledge or theory. How is it that you read certainty into answering "it could" to a question asking if it "could possibly"? Rather than saying the universe definitely came into existence without a cause, he states that our very best knowledge of the universe most definitely allows for that possibility.

- Are you saying that the first way of Thomas is faulty? I thought Thomas holds the first way as the most evident of all the causes. Are you just focusing on the contingency of the universe and therefore not arguing about motion?

That is a helpful way to phrase it as it gets us to the validity behind Vogt (and others, etc.) who have patiently asked for this supposed new set of definitions whereby resolution emerges. Carroll hints but does not offer and given his goals that just won’t do. Where is the evidence that either the universe or the *god* which begets her overcomes both contingency in the weaker sense and contingency in the stronger sense? Also, where is the QED? What we get, have gotten, so far at least, is not an answer but merely just-so-hints that there is, if we only allow the possibility, lurking somewhere in the recesses of the Non-Theist’s mind, a secret body of evidence. But what we never see is the actual evidence itself, the actual QED/demonstration itself.

Since we have not seen those three – and reason rightly demands all three – then reason and science and the evidence assure us that it is the Christian, and not our Non-Theist friends, for whom this entire affair is “…not an expression of blind faith but precisely a condemnation of blind faith…”

The Non-Theist has either [1] the universe as we know it (all of physics, etc.) or, he has [2] his *god* which begat the box we call [universe]. Perhaps [2] is that which sums to be Hawking's South Pole, as it were, while the universe is not *god* but rather the begotten of *god*. That there is nothing south of the South Pole merely brings us into the timeless, spaceless etc., but "that" is laced through with contingency based on everything that Non-Theism has offered so far. It makes no difference where we draw that line for whether [1] Non-Theism’s *god* which begets the universe is one's terminus of explanation, or whether [2] the universe is the whole show, is one's explanatory stopping point, then, either way, we are back to T-zero (Bang etc., etc.) as either a part of *god*, or a potentiality with respect to *god*, or a change in *god*, and therein *god* itself reduces to contingency. By that I mean the following:

It's unclear what to make of the Non-Theist's proposed *god* with respect to T-zero (Bang, etc., etc.) given that T-zero must be [1] "always” and “already" a "part" of the proposed *god* or, [2] T-zero must be an entity which came "out of" that *god*, which loops us back to [1], or, [3] T-zero must actually be *change* of some irreducible sort, forcing potentiality and sacrificing pure actuality. Hence it's not obvious that the proposed *god* escapes either parts, or change, or potentiality, and therefore reveals contingency (in several senses). We can add that we also find deflationary truth values on our end as the illusory presses in (though that is, technically, a separate topic….. although it does (quite harshly) impact any move by the Non-Theist to offer us his reasoned QED as per the earlier link).

It’s just not obvious based on that which our Non-Theist friends including Carroll have offered so far that their paradigm’s tools can even in principle dissolve the problems of contingency in either the weaker sense ( http://edwardfeser.blogspot.com/2013/05/avicennas-argument-from-contingency.html ) or in the stronger sense ( http://edwardfeser.blogspot.com/2013/07/avicennas-argument-from-contingency.html ). In the same way, again, the reasoned demonstration ( http://edwardfeser.blogspot.com/2014/09/qed.html ) of a supposed QED built atop some new syntax is, also, it seems, even in principle untenable.

Edit: “Naturally, if it is the ultimate source, cause or explanation of things it is actual or existent – it could hardly cause or explain anything otherwise – but it is not a compound of actuality and potentiality as other things are, nor a compound of existence and essence. It would have to be, always and “already” as it were, pure actuality rather than something that has or could have any potential in need of actualization. It would have to be, not “an” existent thing among other existent things, but pure being or existence itself. Anything less would require a cause or source of its own and thus not be the ultimate cause or source.” ( from E. Feser / reviews the book, “The Mystery of Existence: Why Is There Anything At All?” at http://edwardfeser.blogspot.com/2013/10/why-is-there-anything-at-all-its-simple.html )