Opening the conversation is the first and hardest step with a devoted follower who has been subjected to undue influence. The first barrier will always be confirmation bias: we accept information that agrees with our beliefs and reject information that does not.
When our core beliefs are challenged, we experience cognitive dissonance – and the experience is often physiological as well as psychological. We wobble when disagreed with. Many people simply push away any challenge with thought-stopping: they either demand that you shut up, or they simply stop listening.
It is noticeable that academics often preface their comments with a disagreement – they say, “No” or “But”. This immediately and automatically rouses defenses. It is much better to frame even a disagreement with, “Yes, and…”, if you want someone to listen to your position. And pay attention to their facial expression to be sure that you are getting through.
When successful, exit-counseling is an exquisitely balanced communication. The counselor does not challenge the fervent believer, and does not raise the ego-defenses; instead, shared goals create rapport– both the counselor and the subject want to find the truth. And the counselor must always want to lead the subjects to think for themselves – even when that thinking causes cognitive dissonance for the counselor!
It is important to be courteous, to allow the person to fully express their thoughts and beliefs, and to acknowledge their successes in the relationship or group, so that they will feel comfortable discussing any failures. Only friendly discussion lowers the barrier of confirmation bias. Any attempt to prove the believer wrong through evidence and rational argument will fail, until the believer is ready to take charge of the enquiry.
It sounds easy, but it can take a long time to create this friendly exchange when you are dealing with someone whose distrust of outsiders has been amplified by a group leader or abusive partner. Take that time: it is well worth it!