Atheist Memes

Ive had an idea in my head for a bit for a sci-fi setting that youve just reminded me of, where humans have sent out a number of colony ships to the closest hundred or so nearby stars- and almost all of the ones that have succeed have been crewed by cults, very dedicated religious groups and similar, or at least very dogmatic and extreme ideologies, because those had been the kind of group to be willing to spend all the money to create a starship with no real possibility of profit from it, had the zeal and skill at propaganda to instill a singular sense of mission across several generations, and had the desire to create their own society away from everyone else in order to make everyone there follow their rules. It then would have created a bit of a problem where, several generations down the line when this colonization wave has resulted in fairly large and powerful civilizations around the nearby stars, a sizable fraction have ended up seeing their journey as some kind of semi-mythical exodus from some kind of lost homeland that they've assigned religious importance too, and sent crusades back to the solar system to reclaim, putting them into conflict with both the people still living around Sol and all the other factions doing the exact same thing at roughly the same time, only ending when their own colonies of offshoot groups and exiles start doing the same thing to them and distracting them from being able to send crusader fleets.