Why would history repeat? [closed]

Question

I'm working on a little project in where humanity has expanded beyond the known solar system to it's fringes and constructed numerous, large spatial stations that have their own atmosphere, some with the length of Earth and others orbiting the sun as a Dyson ring. Humanity has also developed into subspecies due to the colonization of other planets and bio-engineering as well as cybernization. The world is dystopian in most places too.

But that's beside the point -- I just wanted to show the state the world's in.'

The questions and more details:

There is a recurrence of religions at the time -- or at least powers that are inspired by the times of the Crusades. A large faction is repeating the Crusades with futuristic technology, warring against other factions and taking their territory and resources. They also have a similar aesthetic to Warhammer 40k's Space Marines and The Culter Die from E.Y.E Divine Cybermancy.

Finally, my questions are:

1. Why would history repeat like that? I don't want to simply say "Because humanity just wants to and stuff. Roflmao."
2. What would cause a resurgence in religion?
3. These Crusaders and men/women of their faction are highly altered -- to the point where one modified by their faction can survive for more than 300 years. I plan one explaining that such changes can only be done to the exclusive true-believers -- yet why doesn't the everyday human have such enhancements?

Thanks, and I hope I'm clear enough.

Answer 1

1. Why would history repeat? The answers are legion, so I cannot give them all. However, one of my favorites for world building purposes is to argue that there are some universal patterns which human nature cause to appear. They may be the crusades in one life, or a cyber war to reclaim the internet in another. The actual events usually change (exact repeats of events usually require substantial handwaving on the author's part), but the relationships between the players stay the same. I find this pattern is effective for worldbuilding because it makes it easy for a reader to see value in identifying those relationships in their own life.
2. What would cause a resurgence in religion? Religions usually surges forward after secular life overreaches (and vice versa). Simply have the local regents over step their bounds, or have the local scholars claim to know more about the future than they reasonably can predict.
3. Why doesn't the everyday human have such enhancements? It is not uncommon in lore to have a modification, item, or ability which is unsafe to use without tremendous study. One of the common arguments regarding Lightsabers in Star Wars is that only Jedi/Sith carry them because they are simply too dangerous to the wielder without Force reflexes (as seen by General Grevous's demise, also Darth Maul is one of very few who can safely wield a double edged lightsaber without hurting himself). This is not uncommon because specialized weapons are often designed for specialized castes. Consider our military pilots. While an average person could probably take off and fly safely in a commercial plane, fighter planes have so much capability that that average person would likely be planted under the daises the instant they try to flex the fighter plane's metallic muscles. Now if there was a religion built around piloting (a real one), it would not be unreasonable to craft the plane's capabilities around what members of that religion communally understand. It would be impossible to learn to fly it without accidentally becoming a true believer along the way.