All of the songs on this cast recording are very funny. It is all irreverent, but what do you expect from the creators of South Park.
This song, is funny whether you have gone on a mission, or live in a Mormon area, or even if they have just knocked on your door. Take it with a grain of salt. I mean no disrespect. The song is just funny.
“Hello would you like to change religion? I have a free book written by Jesus!”