In the last session, my party, who have been having a great time doing quests for my warlock patron, have suddenly realized that maybe they're a bad dude after they killed a child (using the Rogue like a puppet to do so) and then had us brand our children with their symbol. Now they know why I have been so reticent and cryptic for the whole campaign.
Personally I'm just relieved that we finally are all on the same page. It was a bit frustrating seeing the Rogue get sucked into the cult and ignoring all the big red flags on the path to hell.