I would say that 50% of my business is with churches or church groups.
I have never had a problem with my songbook. I have two songbooks however. 1 PG rated the other is for bar gigs.
If you are playing in a church hall, you will find that the people actually govern themselves.. they don't want to sing something offensive!
I have played in Catholic, Lutheran , Methodist and even Southern Baptist churches with no problems.
Bubba