It has everything to do with shortening the distance!
You see there was a prophecy among the Bene Gesserit that a careful human breeding program could produce a genetically perfect man who could survive taking the water of life. This would enable in him an ability similar to that the Guild Navigators employ to guide their ships, but for the course of all humanity rather than the course of a single heighliner.
This gave me a good head scratcher. Taking the terms to be religious, I started to unravel it.
Bene Gesserit sounds like it would be Hebrew or Yiddish ("sons of decree" or something like that) although Google Translate does not hesitate to call it Latin. Water of life sounds like too common concept to trace it back to any specific religion, but Guild Navigators? Now that sounds like a more modern concept, and I would not be surprised if that was present in Mormon teachings or within the church of Scientology. Finally, heighliner, that's not a type of ship that either me or wiktionary is familiar with, so what are we even talking about?
I would be so lost without the sibling comment hinting towards the fictional world of Dune.
Huh... all these hebrew/yiddish linguistic ties are fascinating. There are other things that hint at Judaism or some evolution of it with the Bene Gesserit:
* They are a deeply matriarchal group tracing lineages more by motherhood than fatherhood. (Although with a more over feminist slant too - in that they are all women)
* They are referred to by some in ways that are similar to antisemitic stuff - schemers, conspirators, shadowy powerbrokers, etc. (although in that universe they actually do that stuff too)
* the mesiah prophecy referred to above
* their beleif system and source holy book are a basis for many religions
* a bunch of random little references throughout the books suggest that their ancestors may have been jewish (10k years ago, back on tera)
Dune is a really really good example of world building - at least the ones written by Frank Herbert. Lots of subtlety, the societies and groups in it evolved from ones on earth, and he pulls from a variety of cultures and religions to create the fictional ones. All of it is presented in a way that isn't super expository, but rather you just have to figure it out as you go in a fairly well written way. I recommend reading them - I think you'd see a lot of interesting stuff in there that I've missed.
Not all clones will survive the pressure of all the expectations upon them, but we only need one of them to accept his destiny as Kwisatz Haderach.