Leah Remini to discuss Scientology on '20/20': 'Being critical of Tom Cruise is being critical of Scientology itself'

Leah Remini is discussing why she left the Church of Scientology in an exclusive 20/20 interview on Friday, Oct. 30.

In an ABC News promo, the actress sits down with reporter Dan Harris to discuss her experience with the Church -- and the reasoning for severing ties with it.

Read More: British Scientology Doc Maker Discusses Taking on the Church (Q&A)

"The decision to leave is you're giving up everything you've worked for your whole life," she says in the clip. "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."

Remini describes during the interview how she and her family joined Scientology when she was a child and continued with her commitment to the Church for 30 years until she parted ways as an adult, according to ABC. "The mindset becomes us against them," she explains in the clip.

"Being critical of Tom Cruise is being critical of of Scientology itself ... you are evil."

The hour-long special airs Oct. 30 at 7 p.m. on ABC.

Read More: Scientology Ramps Up 'Going Clear' Smear Campaign, Contacts Academy Members

See more from Leah Remini in the gallery below!

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