I do not understand why this is such a popular and beloved book. It starts off pretty interesting, with an engineered disease wiping out much of humanity, and for a while, it seems like a story warning people about the dangers of unchecked science, the evils of modern society, and survival in a post-apocalyptic world. But then, without much warning, the book takes a wild turn into a bunch of religious, superstitious, magical, good-versus-evil nonsense. Instead of telling an interesting tale about humans and choice, it's all the will of god and the devil or angels and demons (or Mother Abigail and Randall Flag) and none of the characters have any real choice. They just _are_ good or evil, they are compelled by dreams and visions to do stuff, and none of them really change or grow in any meaningful way. In short, the plot is complete nonsense.
The book, however, is exceptionally long--close to 1,500 pages long. It's full of unnecessary back stories, tangents, and characterization that is an utter waste, since the characters are just flat, unchanging, stereotypes. And some of the stereotypes are a bit uncomfortable. For example, almost all the women are helpless damsels in distress; the characters with mental retardation have magical abilities to detect evil--oh, and so do the dogs; after the plague, it seems like only a bunch of white folks survive, except for Mother Abigail, a god-fearing sacrificial black woman who is well over 100 years old. The writing is awful. Cheesy puns, terrible analogies, uninteresting prose. And the title and cover make no sense. No one really takes a stand, there is no battle, nothing. Just people surviving, having a religious hallucination, and then an exceptionally predictable and underwhelming "climax". Oh, and then the book drags on unnecessarily for a few more hours.
If you're actually interested in post apocalyptic tales, don't waste your time on the boring, pseudo-religious nonsense of the Stand. Instead, check out The Road, I Am Legend, Oryx and Crake, Children of Men, and World War Z.