The son of a Hamas leader did become a Christian.

"Mr Yousef said that his doubts about Islam and Hamas crystallised when he realised not all Hamas leaders were like his father, a moderate who he describes as "open-minded, very humble and honest".

Mr Yousef said that he was appalled by the brutality of the movement, including the suicide bombers seeking glory through jihad.

"Hamas, they are using civilians' lives, they are using children, they are using the suffering of people every day to achieve their goals. And this is what I hate," he said. "
http://www.telegraph.co.uk/news/worldnews/middleeast/palestinianauthority/2613399/Mosab-Hassan-Yousef-son-of-Hamas-leader-becomes-a-Christian.html