Old Shame: Margot Kidder didn't realize that Tribulation was Christian propaganda until she was nearly through filming. Apparently (and understandably) she didn't understand the plot until the end, when the Anti-Christ goes on a Motive Rant. Margot Kidder was an avowed atheist. People coming up to her and praising her work in said movie tended to be a Berserk Button for her.
The Other Darrin: Sam Bornstein played Franco Macalousso in the first movie, which was later played by Nick Mancuso in the following movies.