I've been using my shower with just dry wall up for months now (don't ask :) Anyway, there's a little bit of mold, I'm guessing, on a small section of the wall. I'm finally ready to put up some tile.
Do I need to replace the dry wall since I've been abusing it with the shower before I put up new tile. Can't I just let it dry or spray something on it?
Drywall shouldn't be in the shower. Take it down and replace with cement board. This will cost you $50 and will ensure the money and time you put into the tile last more than a year.
If for some odd reason you are using a Kerdi membrane or something like that (which your question leads me to think you are not) than you could keep the drywall. You would have to scrape off the mold and hit the drywall with a anti-mold spray. If the mold doesn't scrape off then you need to replace that section of drywall.
