i have a lot of religious kids working for me. we had a lot of debates about religion and political debates...
some of the views are amazing.
ignorance is bliss. sounds like his family doesn't want to acknowledge some major issues and problems in this world.
i'd approach him like a kid who does really know anything ,and ask him questions which will make his contradict each other to make any point you're tryin' to make more valid.
also, they say the happiest people on earth are buddist priests.
i'd love to hear his def. of the devil, if he even has one.