There is a certain creature that English people call a cow. French people call it la vache. Doubtless other languages have other words for the same creature.
Now, does it make sense to ask the Frenchman to justify the use of 'la vache' to describe the cow? Imagine asking the question (in French, presumably) 'why do you call it la vache?'!! There is no exterior logical justification for the derivation of the language. There are cows, and this is the language that we use for interacting with them.
So I want to distinguish between two sorts of justification for God-talk (theology). One sort accepts that there is something there to be discussed, and the debate is therefore about what sort of language does the best job in the discussion. Let's call this the 'naming God' debate.
The second sort denies that there is anything there to be discussed at all. As Richard Dawkins puts it (in 'God Delusion'), theology is simply 'fairyology' - there are no fairies at the bottom of the garden, and it's a waste of time pursuing any conversation involving them. So lets call this the fairy-killing debate.
Now, in a post which will come along soon, I'm going to be talking about conscience, and talking about how God-language interacts with language about conscience, morals and decision making and so on. When this has come up before, eg when discussing my post about 'what I mean when I talk about God' some of the responses have, it seems to me, been akin to asking the Frenchman why he uses the word 'vache' to talk about cows. In other words, the reality of what I am describing is not in dispute, simply the merits or demerits of using religious language to describe the phenomena. I have a lot of respect for those perspectives which recognise what is trying to be described using god-language, engages with it, points out its flaws, and then starts being linguistically creative (possibly in atheistic ways) in order to move forward. _Some_ of the discussion around the problem of evil can be like this (but most isn't).
However, some of the criticisms have ended up obsessing over the question of whether a particular entity exists or not. In other words, the discussion has been about fairy-killing. Now, as I've explored elsewhere, I don't find the fairy-killing discussions all that helpful, not least because it's part of the logic of faith that God does not 'exist' in the relevant way for the discussion to make sense. That is, as the quote from Denys Turner I refer to often puts it, "in the sense in which atheists… say God ‘does not exist’, the atheist has merely arrived at the theological starting point. Theologians of the classical traditions, an Augustine, a Thomas Aquinas or a Meister Eckhart, simply agree about the disposing of idolatries, and then proceed with the proper business of doing theology."
This distinction corresponds, I think, to the distinction between the sophisticated and the humourless atheists. The sophisticated atheist recognises what is being talked about; the humourless doesn't.
Anyhow, this was really a ground-clearing post. Consider it a 'clearing of the throat before speech'.