James McGrath has a great post up called Agnostic Christianity: Faith for a New Year. In it he has this to say about Christian agnosticism:
For me, the answer to the question someone asked recently about Christian agnosticism is that there not only can be Christian agnosticism, but that in fact that is all we have. There are no people who have actual historical certainty about every historic Christian claim about Jesus. There are only people who have managed to attain a feeling of certainty. But being honest about the uncertainty, even though it can be unsettling to feel it, is not at all something to be ashamed of. Instead of describing it as "agnosticism" we could also call it "honesty."
For me, it's a matter of integrity. I would be intellectually, morally, and religiously lacking in integrity if I was not honest about the necessary doubts that come with faith. Agnosticism is a good and accurate word, but I prefer to call it honesty.
Honesty is more meaningful to me because it highlights that we are not doubting just because it's cool, but because it is really part of our faith, part of who we are. I am always concerned when someone feels 100% certain about their views. I simply try to be honest about what we can and can't know and then express my beliefs in a manner that is clear that these are my beliefs, not things I know to be true, as that would simply be a lie.