This was my response to someone who thought that there would be world peace if the entire world converted to Islam.
Even if the entire world converted to Islam, there would still be war and fighting. When the radical Muslims are not bombing and attacking us, they are bombing and attacking other Muslims who they do not believe are Muslim enough. They are like every other religion when they don't have an outside enemy, they fight amoung themselves. The only way there will ever be peace on earth is if it becomes a burnout cinder orbiting the sun.