The Heal Chapel is located in Sunfall Village, just to the right of your house. Once inside, just click on the Healer and he will heal your miscrits. You have to wait one hour between heals, or you can pay one Facebook Credit to heal instantly. If you want to pay with credits, come here instead of the Arena, which will cost you 2 credits.
Edit: The currency used to pay the healer is now Virtue. 1 point of virtue is equal to 6 minutes of waiting time. Virtue is stored in your inventory bag near the bottom right side of the page (next to the map button). Also it is now 5 Facebook credits to heal if you don't have a full bar of 10 virtue to pay the healer.