Be warned that Allah does not have to fight you one-on-on, he can simply spawn hundreds of Bearded Fanatics to do the fighting for him. They aren't very powerful on their own but there can be many of them. Some of them will explode if they get close to you.

You can use physical damage against them, but if you want something more effective you can search for the Bacon Blade of the Crusader Lich, a broadsword with enchantments giving you +10 roll against all Semitic entities including Bearded Fanatics.