Author of Inside Scientology Sits Down with INSIDE EDITION

INSIDE EDITION talks to the author of the new bestselling book "Inside Scientology" that says it reveals little-know secrets about the controversial church.

Action Hero Tom Cruise was allegedly frightened of weapons until the man who runs the Church of Scientology, David Miscavige, helped Cruise overcome his fear.

According to author Janet Reitman, Cruise and Miscavige "shot skeet for a few hours until Tom got more and more comfortable with guns."

This is just one of the claims made in Reitman's new bestseller Inside Scientology: The Story of America's Most Secretive Religion. Reitman, a Rolling Stone magazine writer, spent five years researching the controversial church.

"Scientologists look at Tom Cruise as the epitome of what a great Scientologist should be," Reitman told INSIDE EDITION.

Reitman wrote that Cruise was once "uncomfortable" being known as a Scientologist. "He walked around in sunglasses and a baseball cap at the [Scientology] base," she wrote.  

She also alleges that Elvis Presley once seriously considered becoming a Scientologist. At the time, he was dating actress Peggy Lipton, and she took him to the Scientology Center in Los Angeles.

But according to Reitman's book, Elvis walked out of the meeting, saying "[Expletive] those people! There's no way I'll ever get involved with that [expletive]-ing group. All they want is money."

Interestingly, Presley's wife Priscilla and daughter, Lisa Marie, would later become devout Scientologists.

In a public service announcement from the early 80s, leading personalities of the time including Kate Jackson, Bob Hope, Henry Winkler, and Magic Johnson promoted the concept "get high on yourself." The ad was produced by a Scientologist, who had other members serve as volunteers on the set.

"Every single celebrity was assigned a Scientologist," Reitman wrote.

"They were there to get to know celebrities and to forge relationships with them so that maybe, ultimately, somewhere down the line they might interest them in becoming members of the church," Reitman told INSIDE EDITION.

And get this: anyone who wants to become a part of Scientology's upper level management, known as the Sea Org, is required to turn over his or her life to the church.

"When somebody decides to join the Sea Organization they sign a contract for one billion years which is symbolic of their entire lifetime on this earth," said Reitman.

The Church of Scientology also has a secret language.

In a Scientology produced video, Tom Cruise mocked "SPs," which is short for a "Suppressive Person," or anyone who leaves the church without permission.

Other words in the secret language include "thetan," which means soul or spirit, and "enturbulate," which means upset. Upstanding members of the secret world are called "in-ethics."

"They are a parallel universe, and yet, they're very integrated into the mainstream world," Reitman said.

The Church of Scientology sent INSIDE EDITION a statement saying that the sources Ms. Reitman used for her book are unreliable, biased and admitted perjurers. The church has also said the book is filled with inaccuracies and is not well-researched.