Only one problem - another member of the party is a rogue with a ring of invisibility. Up until now, the cleric's been satisfied casting Invisibility Purge every time he notices the rogue slip his ring on. The DM feels that with a dedicated purpose, though, things would have to step up a notch.
I'm looking for a way to make this work. The only idea I've thought of so far is that the cleric's trying to somehow convert the rogue through example, but that seems like a copout. Any advice is appreciated.