Clue's in the title: your job is to pray for little Johnny/Miranda and keep an eye on their spiritual development - same as it's always been. You could easily decline on the grounds that you have no strong religious feelings. 'Renouncing the Devil, et' is pretty strong stuff, so if you don't believe it, don't do it. I suspect that apart from being a jolly nice chap, you are stinking rich hence all the requests.