In Dune, Paul Atreides led a jihad, not a crusade
aljazeera.com
aljazeera.com
Dune is 20k years in the future when Earth doesn't really function anymore. I think it's pretty reasonable that our current views on religion and race will be long, long gone by then.
For example, the Orange Catholic Bible is an important religious text which is a syncretization of several religions with clear roots on Earth - https://en.wikipedia.org/wiki/Dune_(franchise)#Zen_and_relig...
> Orange Catholic Bible: the "Accumulated Book," the religious text produced by the Commission of Ecumenical Translators. It contains elements of most ancient religions, including the Maometh Saari, Mahayana Christianity, Zensunni Catholicism and Buddislamic traditions. Its supreme commandment is considered to be: "Thou shalt not disfigure the soul."[110]
The Fremen are Zensunni - "What is beyond doubt is that the Zensunni belief was an amalgam of two ancient religions: Sunni Islam and Zen Buddhism" says https://dune.fandom.com/wiki/Zensunni .
Take Islam away, and the "Sunni" in "Zensunni" seems pointless.
But the text shows that some aspects of modern-day religion are still present. Here are two examples from Children of Dune:
The O.C. Bible has "Maleficos non patieris vivere", from the Latin Vulgate, Exodus 22:18. In KJV this is translated as "Thou shalt not suffer a witch to live", which is also the translation used in the story - https://archive.org/details/dunemessiahchild0000herb/page/26... .
And knowledge of St. Thomas of Canterbury (saint in the Catholic Church and the Anglican Communion) survives:
> Leto crouched in the lee of his dune and waited for the night to settle into its own rhythms. Patience and caution—caution and patience. For a time he amused himself by reviewing Chaucer’s route from London to Canterbury, listing the places from Southwark: two miles to the watering-place of St. Thomas, five miles to Deptford, six miles to Greenwich, thirty miles to Rochester, forty miles to Sittingbourne, fifty-five miles to Boughton under Blean, fifty-eight miles to Harbledown, and sixty miles to Canterbury. It gave him a sense of timeless buoyancy to know that few in his universe would recall Chaucer or know any London except the village on Gansireed. St. Thomas was preserved in the Orange Catholic Bible and the Azhar Book, ... - https://archive.org/details/dunemessiahchild0000herb/page/43...
This implies that at least a couple current views of religion remain.
[1] https://scottlocklin.wordpress.com/2021/01/21/the-fremen-are...