"Show me just what Mohammed brought that was new, and there you will find things only evil and inhuman, such as his command to spread by the sword the faith he preached." - Manuel II
I am interested in hearing the opinion of Muslims and non-Muslims alike. I can't think of a single element of the Muslim religion that wasn't (i) already established or preached by previous religions, (ii) a religiously unimportant convention, or (iii) evil and inhuman.
An example of category (i) is e.g., monotheism, which is an integral part of Judaism.
An example of category (ii) is praying towards Mecca.
An example of category (iii) is Muhammad's commandment to slay the unbelievers.
So, what Islamic innovation isn't covered by (i-iii) but belongs in a category (iv) of good and positive innovations brought by Muhammed?