Christian Amondson has an interesting post on issues of incommensurability, i.e., how communication can happen across narratival boundaries. Here’s my comment:

Do we want to say that the incommensurability between the Christian world/narrative is essentially different from the incommensurability that exists between other worlds?

Some worlds are thin enough that they are by necessity incommensurable. Football and baseball are so thin that though both are sports/games, there is no room for overlap, no way to sensibly (from either perspective) play both at the same time.

When it comes to Christianity and other worlds/narratives I have a few ideas.

1. Those of us that inhabit the Christian narrative also inhabit other narratives. While our primary allegiance may be to Jesus and his story, we are also always immersed in other stories, our broader culture in particular. Because of this we, at the very least, jostle up against those whose primary allegiance lies in a story other than Jesus’.
2. God is a participant in the ongoing Christian story. As that story impinges on other stories through those of us who embody it, our jostling with participants in other stories is more than just us. Through us God is invading their territory.
3. There is no guarantee that the sense God might make to the inhabitants of other narratives through us will make any sense to us. It’s also likely that what God does won’t make sense to the inhabitants of those other traditions. BUT – and I think this is important – the non-sense that God’s work through us makes can serve as a crowbar to pry open their eyes (I speak figuratively) and arouse questions that can draw them to Christ.
4. One of the chief forms of jostling that we see in Scripture is suffering. Thinking of 1 Peter, we see the admonition to always be ready to give an answer for the hope that we have. While I was long taught that this meant (roughly), “Study the Josh McDowell books so you can quote their arguments to non-believers,” the context is actually critically different. Rather than assuming the issues are primarily intellectual, Peter’s assumption is that by following Jesus we’ll run smack into the world and suffer for doing so. But the Christian way of embracing suffering will be so non-sensical and strange to outsiders that they’ll be compelled to ask questions. THAT’S when our answers come in.
5. Finally, I’m not a Barthian. I think God as creator plays a role in every culture or narrative out there. The role may be deeply hidden, hard to find,  unpredictable. But some how, in some way, God will be there pointing the way to Christ. So when we come along – whether in strength or weakness (if the NT picture is normative and not merely descriptive, weakness will be more common than strength) – and impinge on or jostle with their narrative/world, then it can be an occasion for God saying, “See! This is what I was trying to tell you about!”