I read The Hobbit as a kid (hoping to re-read it before the movie), but even now I still remember this passage where Bilbo is in the tunnel going down to meet Smaug. This would make an awesome sermon illustration about courage:
It was at this point that Bilbo stopped. Going on from there was the bravest thing he ever did. The tremendous things that happened afterwards were as nothing compared to it. He fought the real battle in the tunnel alone, before he ever saw the vast danger that lay in wait.