Leah Remini is opening up about her time in the Church of Scientology as well as her decision to leave the organization.
In a sneak peek at her sit-down interview on 20/20, the former King of Queens star gets candid about her experience in the church and how the environment became something she didn't want to be a part of.
"The decision to leave is you're giving up everything you have worked for your whole life," she shared with ABC News' Dan Harris. "I feel that people need to understand this has been my whole life and I want them to understand how it happens."
She continued, "As time goes on, you start to lose touch with the real world. The mindset becomes us against them."
The new clip also has Remini opening up about a famous member of the Church of Scientology. As it turns out, talking bad about Tom Cruise may have its consequences.
"Being critical of Tom Cruise is being critical of scientology itself. You are evil," she alleged. Harris goes on to ask, "If you knew Tom Cruise was watching this, what would you say to him?" The full interview is expected to air Friday night at 10 p.m. on ABC.
The revealing interview comes before the TLC reality star is releasing a new book titled Troublemaker: Surviving Hollywood and Scientology.
According to Ballantine Books, the memoir will be a "moving and eye-opening account" of Remini's 30 years within the church. "Bold, brash, and bravely confessional, Troublemaker chronicles Leah Remini's remarkable journey toward emotional and spiritual freedom, both for herself and for her family."
Since leaving the church, Remini's daughter has become baptized in the Catholic Church where the family celebrated "new beginnings."
"For the record @leahremini and I have always been Catholic," Remini's husband Angelo Pagan wrote after the ceremony. "It was a beautiful experience and our little angel is on her way to a more spiritual existence. God Bless!"
Remini's new book will be available for purchase on Nov. 3.