Passive effect: His aura is very strong and can reach a fair distance, bolstering the spirits of those within. Benefits can include things like: Have less fear and anxiety, feel more confident and optimistic about our chances, it suppresses the effects of evil and darkness, makes healing more effective, and if someone benefits from "Holy" then this likely counts. (All this is of course up to the individual player.)

(In D&D terms, it's like a high level Paladin's aura)