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Jehovah Witnesses believe the Watchtower is the sole channel of communication between God and mankind. They have been systematically conditioned, through hours of indoctrination each week, not to question anything. Actually, they must accept every teaching of the Watchtower or be disfellowshipped and shunned. They have been taught to fear former members, whom they call apostates. They have been told we are bitter, angry people who want to destroy the faith of the all JWs.
This is so deeply ingrained that JWs become fearful when exposed to anything critical of the Watchtower. If what they taught was really "the truth" it would hold up to scrutiny, but the logic of this escapes them because of the indoctrination. Most JWs know very little about their beliefs or the history of the organization. They are told the destruction of this system is happening soon and the only way to survive is to become a Jehovah's Witness. They don't know the religion has incorrectly predicted the end many, many times over the last hundred years, and then turns around and pretended it never happened. These dire predictions keep people fearful and compliant.
If you want to help your boyfriend, you need to research cults and how they work. It's very difficult to get an indoctrinated cult member to think and see what has been done to them, but it can be done in some cases. Nobody in a cult thinks they are actually in one, so you have to approach it very, very carefully. Many people recommend Steve Hassan's book, Combating Cult Mind Control. For a short description of cults I like howcultswork.com.