Remember that most Christians have been such their entire lives. This programming is deep, and more strongly cemented than their critical thinking skills.

I suggest backdooring in critical thinking skills. When helping do deprogram my ex-in-laws we did weekly brain teasers and logic puzzles before our dinners, and after we’d play investigative board games.

Eventually they left the baptist church, citing they’d been listening closer to what thwjr pastor was saying and it made them uncomfortable. They’re still Christian, but they go to a PCA Church now. Much less hateful congregation and clergymen (are they still clergy if they aren’t Catholic?).

Its all about baby-steps. You have to trust people to learn, but you may want to help supporting some of those learning skills.