Joan of Arc tidbit: she never told people about the voices she heard (with the exception of two confidants), until her trial. She led the armies without telling them about the voice of God. Also, she's the only person who was ever named a heretic by the church and then later canonized.
Unrelated: you should totally read Sloppy Firsts by Megan McCafferty. Great teenage stuff, so satisfying, funny and sharp.