Keith Parsons has come up with a beautifully-written paper entitled No Creator Need Apply: A Reply to Roy Abraham Varghese. It’s worth reading the whole piece, but this paragraph will give you a sense of the strategy that Parsons adopts:

[Varghese] does tell us that “It is as absurd to ask for an explanation for the existence of a self-explanatory being as it is to ask ‘Why is a circle round?'” (pp. 14-15). Well, yes, it would be absurd to ask “What is the explanation (meaning an explanation external to that being itself) of the self-explanatory being?” But we are still left completely in the dark about just how we are to construe God’s alleged self-explanatoriness, and, in particular, how it would differ from the condition of a putative original, uncaused state of the physical universe. Worse, until and unless we have such clarification of what it means to be self-explanatory, it is hard to see how God’s alleged self-explanatoriness really amounts to anything other than just being inexplicable. If God, by definition, can have no cause or dependence on anything else (since all else is caused or depends on him), then God’s existence is placed beyond the bounds of any possible explanation, account, or understanding. Ironically, therefore, Varghese and Meynell may have only succeeded in defining God into utter inexplicability, and so making him into precisely the sort of ultimate brute fact that they decry.

He also addresses a common theistic sleight-of-hand: the leap from logical contingency to ontological contingency.

But why should any nontheist suppose that the doctrine of creatio continuans has any rational credentials? Why, for instance, would a quark require any metaphysical props to uphold its existence and underwrite its powers and liabilities? Of course, all physical things are contingent in the sense that they might not have existed, but logical contingency does not imply ontological contingency. Just because something might not exist at a given time is no reason to think that in fact its existence is maintained by something else. From the nontheist’s perspective, the insistence upon an explanation of the universe in terms of creatio continuans is just another instance of the propensity of theistic apologists to create a mystery where there is none, and then offer God as the tailor-made answer to the pseudoenigma. As for why existing things remain in existence, nontheists just do not see any mystery here and no need for an explanation.

Indeed. Nicely done.
[Via Mark Vuletic, whose Subucula tua apparet is also well worth a read.]