The primary job of a group healer is to provide some health benefit to the group alternating with Conviction. The healing benefit comes from a few areas: Holy Bolt (will do 300 points of healing per shot), Cleansing (will reduce curses by more than 80%) and a Prayer synergy that will heal constantly at a rate of 25. This is a significant boon when used on the right occasion. The other function can be a major benefit when it comes to dispatching creatures -- lowering resistance by more than 125% and lowering defense by more than 90%. Those are % not points. That means a defense of 2000 becomes 200. And a resistance of 100 becomes -25. Or a resistance of 200 becomes 75.