What does it mean to be a Christian?

What could it mean?

So I'm thinking about starting up some kind of a Bible study or maybe more like getting a group of people together to try and have some of this open dialog space. It would be so great to just have some interesting conversations with people and see what they think about the stories. I'm hoping for a good skeptic or two.

So to brainstorm what we'd talk about:

What does it mean to be a Christian (or, better yet, a christian?)

--Are there certain things you must do to qualify? Things you must believe?

--Does it require a particular political philosophy?

--What is the spirituality of being a christian?

--What is the cost of being a christian?

--Why would anyone in their right mind become a christian? :-)

I think there could be some good stories in the Bible about these things, but more as founding stories--principles--than as strict guides.

Suggestions?