What can Christianity offer that nothing else can?

I was away on our communities weekend this weekend. The speaker was quoting Yancey from 'What's so amazing about Grace?' (I think)

Apparently Yancey was asked by some reasonably famous (can't remember who) 'What can Christianity offer that nothing else can? I can find social awareness elsewhere, I can find charity elsewhere, but what can I find in Christianity that I can't anywhere else?'. Yancey's response was 'Grace'.

Now, I tried to find this quote, but couldn't. So it could be wrong.

However, as I listened, something didn't sit right with me.

Two things struck me

1- who are we to think that we are the only channels of God's grace? That we are the only ones in whom His grace can be found!! That the only place to find Grace is within the Church!?!

2- If I was asked this question, I would have answered differently. I would have answered with a question. I would have tried to get at why he was asking his question. To get at the consumerism behind the question. Because, to me, any approach to God that begins with 'what can I get out of it' or 'what can I get here that I can't anywhere else' or 'why should I join' is destined to fail from the beginning.