Christianity, according to Richard Dawkins.
Atheist Richard Dawkins: Christianity Has the Power to Defeat Radical Islam - World Religion News

According to him, the teachings which have been outlined in the Bible and conveyed by Jesus do not promote or encourage violence. It also does not lead to suicide bombings being attempted. Therefore, Dawkins now feels that Christianity might be the best defense for people if they would like to win the war against radical Islam.
Atheist Richard Dawkins: Christianity Has the Power to Defeat Radical Islam - World Religion News