In the film Leap of Faith (1992), was Jonas Nightengale (Steve Martin) putting on the Angels choir just as much as the crowds he "preached" to? Or were they in on it too as a fake "choir"? They seemed pretty convinced and acted as though they really were in the ministry, unaware that they were helping a con man string a bunch of people along. Is this correct, or did I just miss something in the plot somewhere?
In the movie it is never specifically shown whether or not the choir knows or is aware of the scam.
However, on a number of occasions they are present to witness several of Jonas' deceits:
The very first scene, when the police officer pulls the bus over and he takes bets on if he can get off without a ticket. It shows that he's able to manipulate people to the point of making it a sport, which should be a major clue to them
One choir member remarks that Jonas told her one thing about his father right after he tells the crowd something completely different
Some audience members are planted for specific reasons, like giving money to spur others' "generosity", and with glow-in-the-dark crosses on their foreheads which are set off due to a chemical reaction that Jonas is seen testing on the bus. Those plants are likely members of the entourage that the choir would recognize after being on the road with them for so long
Plus, there is all kinds of equipment on the bus that allows it to act as a "command center" during performances, which would certainly raise suspicions to anyone who can think critically.
Based on these events, I'd say it's likely they did know of Jonas' intent. How could they not? There are other scenes, however, where it's less apparent, such as when they first go into the diner and he's doing a little mini-preach to get the waitress' attention, the two women in the choir seem to be very earnestly respondent to his words. I attribute the disparity to the fact that the choir wasn't the focus of the movie and thus it didn't concern the screenwriters as to whether or not to make them party to the scam.