Looking for source of quote about "doing what you should be" The other day I saw a quote I really liked on the board in front of a church as I was passing by. However I don't remember it 100% and wanted to see the source of the quote. 

Unfortunately I don't remember exactly which church it was (there are a few on this one street).

The quote was something like this:

"If you are doing what you should be doing, then you will light a fire to the world."

I think it might be a bible quote but I am not completely sure.
The quote comes from St Catherine of Siena (1347&ndash;1380), a third-order Dominican, theologian, and Doctor of the Church. According to the book Saint Catherine of Siena as Seen in her Letters, it is adapted from a quote in her Letter 386. This letter was written to her young friend Stefano Maconi. The original reads:


  Se sarete quello che dovete essere, metterete fuoco in tutta Italia, non tanto costi.


That is,


  If you are the kind of person whom you ought to be, you will set a fire in all Italy, and not only over there  [i.e. where he is currently].


Pope St John Paul II adapted this in an address given in 2000, saying


  If you are what you should be, you will set the whole world ablaze!


And Wikiquote attributes a similar adaptation to Church of England bishop Richard Chartres in 2011:


  Be who God meant you to be and you will set the world on fire.