Before moving on to agnosticism, it strikes me there’s actually some useful common ground between atheism and Christianity…
The God we do (not) believe in
Christian post-modern philosopher/theologian Peter Rollins once addressed a gathering of atheists and was asked “Given the number of other belief systems in the world, how can you be sure that your own is true?” To which he replied, unexpectedly, something like “I can’t answer for all the other belief systems, but I can be fairly confident that my own isn’t true”.
For the full explanation of what he meant you’ll have to read his excellent How (not) to speak of God (review to follow some day), but basically his idea is that our theology – our view or understanding of God – is always partial, and is also always at least partially wrong. That doesn’t mean we give up on it but that we always hold it provisionally. Rollins speaks of ‘a/theism’, a holding-together of our current view of God with the understanding that that view is inevitably hideously flawed, hugely incomplete and wholly inadequate. We therefore both believe in God and disbelieve our view of God.
I’m told that the Romans originally saw the early Christians as ‘atheists’ because they didn’t believe in the Roman pantheon of gods. Richard Dawkins and others are entirely right to point out that Christians and other monotheists are ‘atheist’ towards a huge range of deities (Zeus, Jupiter, Wotan, Shiva, etc) – indeed, towards all gods but one. Dawkins quite reasonably asks why we then do not simply go one god further and become completely, consistently atheist. It’s a fair question, and one to which Rollins’ answer would be that (at least in part) we can and must do that.
However, the reason why we (Christians) must always be at least partially atheist about our own or any other view of God is not because we believe there is no God, but because we know that no human conception or view of God is the real thing. Christians are atheist towards Zeus and Wotan because they recognise that these are massively flawed and inadequate depictions of the One they dimly perceive and half-blindly blunder to approach. (On the other hand, C.S. Lewis for one had a lot of time for the ‘old gods’, the old myths, because he saw in them glimpses and pre-echoes of Christ in whom alone he believed ‘Myth became Fact’.)
God does not exist
In fact, Christians do actually agree with atheists on one major point – God does not exist. Again though, the reason why they can say this (and say it with utter confidence) is rather different from the atheists’ one. But it’s crucial to the above discussion about Zeus and the other gods.
For Christians and other supernatural theists, God does not exist because ‘he’ (please excuse male pronoun) is entirely outside/beyond/before and other-than the whole concept and realm of Existence. God is not a thing, an object, a concept or a creature within the universe/multiverse. To the theist, God IS. He pre-IS. He is (and is not, because all words fall short) the Ultimate Reality, the Ground of All Being, the Source, the One, the Beginning and End, the Universal, the ‘I Am’. He is not simply Top Being in a hierarchy of like beings; the most-evolved or most intelligent creature. God is in an entirely different category from all that exists.
It’s fairly common to hear people say that belief in God is essentially akin to belief in fairies, goblins, unicorns, or Father Christmas. But the whole point of theism is that God is absolutely nothing like any of these things. They are all things – imaginary things, to be sure, but things nonetheless; by contrast the theists’ God is not a thing at all but is rather the inexpressible Reality upon which thing-ness depends.
So I do have a fair amount of fellow-feeling for atheism. It asks some very good questions, and makes some very valid criticisms of religion and theology. I just come in the end to rather different conclusions.