I think one could be forgiven for assuming, after even only a brief survey, that the primary purpose of religion is to keep women in their place. You would be wrong, of course. Women just aren't that important. The primary purpose of any given religion is to inculcate children into that religion. Some of those children will turn into women and if you inculcate them well enough, they'll keep themselves in their place.
Maybe I'm being unfair. The polygamist practices of the Fundamentalist Church of Latter Day Saints, and of the many other Mormon spin-off sects who also practice plural marriage, are enough to turn you off religion for life, and possibly humanity in general if you're having a really bad day. The mainstream LDS Church, of course, has turned away from polygamy, it being illegal and more trouble than it's worth. Committed polygamists, however, appear to believe that it's a sacrament and commandment so fundamental and important to their faith that they hive off to their own communities and risk arrest for the right to marry, for example, their own 14 year-old step-daughter, or, only slightly less skin-crawlingly, hive their 14 year-old daughters and step-daughters off to be married to other polygamists. If the daughters don't, they will, of course, suffer eternal damnation.
This is one of the religious issues which forms part of the backdrop to the appalling double-murders of a mother and her infant daughter in the Summer of 1984 in Utah by Dan and Ron Lafferty. God told them to do it. They're both in prison now, Dan for life and Ron under sentence of death, protracted for decades on appeal. Neither of them are particularly sorry for their crime. They don't even regard it as a crime. God told them to do it, directly and personally, and they thought long and hard about it before concluding that they'd better get on with it or risk angering God.
Krakauer traces the story of the Lafferty brothers and what led them to commit divinely inspired homicide, tracing the roots of their beliefs through the history of the founding of Mormonism by Joseph Smith and the peculiarly bloody and violent rise of what is now one of the fastest growing religions in the world. Persecution, exile, murder and massacre follow the Saints on their trek across America, inflicted on them and perpetrated by them.
It's a compelling, sobering narrative, and though it examines some incidents in a certain amount of detail, in some ways this serves best as a survey for those unfamiliar with the history of Mormonism. Fellow Irish Catholics will not be surprised to discover that the darkest side of religion is, as always, not the dreadful and violent actions of extremist believers, but the systematic and widespread corruption, abuse and repression of the young and the innocent.