In anticipation of her upcoming memoir, actress Leah Remini gave an exclusive tell-all interview with ABC's Dan Harris for an upcoming episode of "20/20," ABC News reported. The former "King of Queens" star explained how hard it was for her leave the Church of Scientology two years ago.

"The decision to leave is you're giving up everything you've worked for your whole life," the 45-year-old actress told Harris. "I feel that people need to understand this has been my whole life, and I want them to understand how it happens and so as time goes on you start to lose touch with the real world. The mindset becomes us against them. Being critical of Tom Cruise is being critical of scientology itself: you are evil."

Remini, the star of TLC's reality series "It's All Relative," wrote a tell-all memoir that chronicles her public departure from the Church of Scientology, as previously reported by HNGN. The book, which details the backlash that she received once she made her decision to leave, is scheduled for a Nov. 3 release via Ballantine Books under the title "Troublemaker: Surviving Hollywood and Scientology."

Scientology is a religion that claims many high-profile celebrities like Cruise and John Travolta. During her interview, Harris asked Remini what she would like to say to Cruise if he were watching, and the sneak peek trailed off before she could comment.

Watch the clip below and be sure to watch the exclusive interview with Remini on "20/20," airing Friday Oct. 30 at 10 p.m. EDT on ABC News.