system
Given the following post, respond as if you're commenting on Reddit:
human
[Dune] What happened to Islam?

I've been rereading Dune recently, and the parallels between the Fremen and the Muslims of earth -- or at least, people of Arabic descent --- are really clear. Lots of Arabic words, an explicit mention that they were once Sunni, and of course, the desert world of Arrakis.

So what happened to Islam? The novel clearly plays off of the stereotypical fervor the media present very religious Arabic people as, but until Paul Muad'Dib, there was apparently no god-like figure.
gpt
The people who would eventually become the Fremen were once called the Zensunni monks, which implies they came from a fused culture, or at least religion, that blended many things from modern Islam and some things from predominantly Chinese philosophy. The Orange Catholic bible is also a work of the fusion of many different faiths and doctrines. 

So Islam, like most religions in the year 20,000+ have waxed, waned, fused, and become entirely new things. Nothing "happened" to Islam other than the march of time and the natural trend of people to culturally share and move forward.