John Travolta has some advice for people who are hating on his religion - "take time and read a book."

Travolta, who follows Scientology, believes that most people that talk down about his religion just don't understand it.

"People really need to take time and read a book. You know, that's my advice. You can read 'New Slant on Life,' you can read 'Dianetics,'" Travolta, 65, said on "Good Morning America." "I think if you really read it, you'll understand it, but unless you do that, you'll speculate, and I think that's a mistake to do that."

On the talk show he said the religion was one of his main tools that he used to get through the loss of his son Jett in 2009.

"It helped me every step of the way for two years solid," he said.

Scientology is the subject of an HBO documentary, which paints the religion in a negative light, called "Going Clear: Scientology and the Prison of Belief."

Travolta was on "Good Morning America" on April 20 to speak about his new movie, "The Forger," which opens Friday, April 24.

Watch the interview here:

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