Mosab Hassan Yousef, a Christian convert and the son of a Hamas leader, is now working on a movie about the Islamic prophet Muhammad.
Yousef announced the project at a press conference in Jerusalem Tuesday. It was his first visit to Israel since he left in 2007.
"I think this is the time to expose the real nature of Islam," Yousef told reporters.
"Islam is not a religion of peace," he continued. "Islam is a religion of war and most Muslims don't understand the true nature of Islam. This is the time and I would like to announce it today here from Jerusalem, next to the Temple Mount."
In Yousef's book, Son of Hamas, he explains how he worked with Israeli security to stop terror attacks against the Israelis.
Many Palestinians, including Yousef's parents, view him as a traitor to Islam and worthy of death.
"I'm not to be addressed as his mother because he's not my son," Yousef's mother, Rubha told Reuters. "He gave his loyalties to a religion other than Islam. We're Muslims and he attacked our religion."
But Yousef remains unapologetic about his Christian faith.
"Usually people are ashamed when they do something wrong. People love to live in the darkness ... I live in the light. I didn't do anything wrong by saving human life," he said.