Scientology has been under attack for years, and despite claims against the church resurfacing in HBO’s documentary Going Clear, devoted Scientologist John Travolta says his religion is simply “misunderstood.”

“You know, people really need to take time and read a book…that’s my advice,” Travolta, who has practiced the religion for over 40 years, said during an appearance on Good Morning America on Monday, April 20. "You could read New Slant on Life or Dianetics, and I think if you really read it, you'll understand it,” the actor added, when asked why he thinks his religion is so often scrutinized. “But unless you do, you'll speculate, and I think it's a mistake to do that."

Travolta — who, along with celebs like Tom Cruise, credits the religion for being life-changing — also told co-host Amy Robach that Scientology is criticized because of its popularity. "Sometimes when something really works well, it becomes a target,” the Grease alum offered.

"You know, 40 years for me I've been part [of Scientology], and I've loved every minute of it," Travolta recently told the Tampa Bay Times after calling HBO’s documentary Going Clear “decidedly negative.” "My family's done so well with it, and it's a beautiful thing for me,” the Forger star continued. “I’ve saved lives with it and saved my own life several times."

As previously detailed by Us Weekly, HBO’s documentary claims that when Travolta was once going to leave the religion, the church threatened him and his family with a “black PR package” which included “damaging material” from taped sessions during which he had confessed intimate life details.

The star, however, maintains that he hasn’t “experienced anything the hearsay has claimed.”