Firsthand experience. A new clip from Leah Remini's upcoming 20/20 interview reveals what it was like for the actress to grow up in the Church of Scientology for more than three decades.

“Because Scientologists view children as spiritual beings, you’re not treated as a kid,” Remini, 45, told ABC News' Dan Harris. “You’re given a lot of responsibility, your ego becomes extremely inflated.”

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Remini, who was associated with Scientology for more than 30 years until she left in 2013, reflected on why it's hard to defect from the church. “The decision to leave is you are giving up everything you have ever known," she said. "And everything you have worked for your whole life."

The King of Queens actress noted that the birth of her daughter, Sofia, was an important factor in her exit. "I didn't want to raise my daughter in the church because from what I experienced and what I saw, the church becomes everything, your mother, your father, your everything," she told ABC News. "You are dependent on the church. In 10 years, if I didn't want to be connected to the church anymore, my own daughter would be taught to disconnect from me. I didn't want to create that. I didn't think that would be healthy for her."

In another preview clip released this past week, Remini shared how the church is protective of its A-list followers, namely Tom Cruise. "Being critical of Tom Cruise is being critical of Scientology itself," Remini mused, adding that anyone who thinks otherwise is dubbed "evil."

While Remini has publicly denounced Scientology on multiple occasions since her departure, the church released a separate statement to Us Weekly this past May about her claims.

"Given Leah Remini's insatiable desire for attention, it comes as no surprise that for two years she has been incapable of moving on with her life," a spokesperson for the Church of Scientology told Us at the time. "And she remains obsessed with shamelessly exploiting her former religion in a pathetic attempt to get publicity."

Remini's memoir, Troublemaker: Surviving Hollywood and Scientology, will be released on Nov. 3. Tune in to Harris’ exclusive 20/20 interview airing this Friday, Oct. 30, at 10 p.m. on ABC.

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