I’ve been rereading the original Dune novels of late, and I must confess that I had forgotten how fun it is to watch Frank Herbert having a hearty go at the excesses of organized religion. The fourth novel in the double trilogy features a being of preternatural foresight ruling a galactic empire via a fusion of church and state power, sort of like Hari Seldon but with prescience instead of mathematics. Also, he is slowly turning from a human into a giant sandworm. I know, that last part sounds difficult to imagine, but it is perhaps less unimaginable than the merging of various Earth religions into surprising new fusions such as Zensunni, Mahayana Christianity, and the Orange Catholics.
Throughout the book, Herbert calls our attention to the various ways that religion can be used to control the minds of men, usually via the monologues of the God Emperor himself. Here is a representative passage:
Of course, religion isn’t the only system of thought that effectively shields its evils behind walls of self-righteousness. As Jack Vance has recently point out, other forms of ideological fervor (such as nationalist patriotism) can do that, too.
I commend the entire six-book cycle to your enjoyment, and I promise that each one gets a bit stranger than its predecessor.