[q]Ray, how do I do this? Do I pretend for weeks that I am interested and then turn on him? I feel bad if I am deceiving someone. Please share more with me. Any suggestions would be welcome![/q]
What you did is called an interaction. That is, you held a short meeting with a cult member in order to share information which would lead him out of the cult. What I'm proposing is that you simply invest a bit more time at getting the person out of the cult. What you need to do is hold multiple interactions with a person in order to establish a relationship. You are not "stringing him along." Your intent is to show him the truth, but only in bite size chunks that are easy to digest. If you do it too quickly, the person will employ defense mechanisms that have been pyschologically ingrained into them by the cult.
I think you are a wonderful human being for trying to get someone out of a destructive cult. Your interactions with JWs can potentially save lives -- think blood transfusion issue.
I suggest you read more about cults and methods for getting people out of cults. In particular, I recommend reading "Releasing the Bonds -- Empowering People to Think for Themselves" by Steven Hassan.
As an xJW, you have the insider knowledge necessary to really help people. Be aware, it does take time and patience. Who knows, maybe you'll become an expert at this some day and write a book about it.
Lastly, Uncle Penn, it is NEVER morally wrong to tell someone the truth. The truth is just easier for cult members to swallow when they are delivered in small chunks over a period of time.
Peace,
Ray Skyhorse