There's a related sense in which Dawkins’ much-maligned God Delusion touches on this question: one of Dawkins' strongest arguments, it seems to me, is that disbelief in gods is the great point of human commonality. That I am, personally, an atheist certainly does not disqualify me from talking about religion. Without exception, every intelligent Christian and Muslim I have ever met has been emphatically atheist with respect to almost all the forty-thousand gods humanity has worshipped at one time or another. Atheism – a refusal to be credulous, a proper intellectual scepticism and dialectical open-mindedness – seems to me the default position of the healthy, sapient psyche. My intelligent Christian friend and I concur in our atheism concerning animistic tree-spirits, the river Scamandar, the divine Emperor Augustus, Wotan, Quezocoatl, Cthulu, the Flying Spaghetti Monster. Of course, we disagree on one specific example: the Christian trinity, which my friend believes divine and which I do not. But to worship the Christian trinity and not to worship the divine Emperor Augustus is, in part, to predicate one's faith on selective atheism.
Or to put it another way. Leafing through old copies of Journal of Theological Studies, as I like to do, I came upon this quotation from David Pailin, (April 1997):
Examination of the content and status of claims about the reality of God has led some theologians to conclude, to the surprise (and annoyance) of many believers, that religion will only have a healthy future if it abandons such claims. For them, as Alasdair MacIntyre once put it, ‘understanding Christianity is incompatible with believing in it’ because its ‘form of belief … has lost the social context which once made it comprehensible.’Because the crowd I hang out with includes a lot of university people, many religiously observant ones included, I’d say the religious people I know would tend, in my experience, to endorse this statement. Certainly, they find Dawkins’s attack on religion to be irrelevant to, or crudely misrepresentative of, their own praxis and beliefs. But I find it hard to believe that most of the world’s 4 billion religious humans (not just the fundamentalists, neither) would find such a claim acceptable. For them the reality of God is surely a simple truth. It’s the difference, there, between the “…has led some theologians to conclude…” and the “… to the surprise (and annoyance) of many believers”.