The first thing to know about “Sex Cult Nun,” and to get out of the way, is that the lurid title doesn’t remotely capture the flavor of Faith Jones’s thoughtful, carefully recounted memoir. Not to imply the book is not disturbing. There are many images you will wish you could forget, and descriptions of sexual mores and practices that call into question basic human values. But there are no nuns, and Jones’s life was anything but chaste, though not by choice.

Jones was born into the religious cult founded in 1968 by her grandfather, David Brandt Berg. Originally called the Children of God, the name was later changed to the Family after one of many rounds of well-deserved bad publicity. You’ve probably heard of it: Among previous survivor memoirs are “Not Without My Sister” (2007), and this year’s essay collection “Leaving Isn’t the Hardest Thing,” by Lauren Hough. This was no tiny splinter group of crackpots, but rather a highly organized international group that ran for almost 50 years with some 10,000 live-in disciples in 170 countries. Its extensive, secretive bureaucratic infrastructure involved so many acronyms and neologisms that the author provides a glossary.

Jones, who grew up in an isolated village in the then-Portuguese territory of Macau, located on the south coast of China, explains: “Each country or region has a WS [World Service] Home, but the locations are a closely guarded secret. When people go to WS, they can disappear for years. They cannot leave or even call their own children to protect the secret. Macau is too small for a WS Home (it would be nearly impossible to operate one without detection), so we send our TRFs [Tither’s Report Form] to the WS Home in Japan. TRFs must include detailed accounting of all income, expenses, members’ personal information, and outreach statistics. A Home that fails to submit a TRF will be excommunicated, cut off from the source of God’s Word and fellowship. No one wants to be labeled a ‘Backslider,’ a person who has turned their back on God and slid back into the cesspit of the System.”

The System, as cult members refer to the rest of the world (the people who live in it are “Systemites”) may be a cesspit, but it’s hard to know what word to use for the moral insanity that grew out of the Family’s “Law of Love,” a doctrine of complete sexual freedom that until 1987 encouraged adult sexual relations with children. The author remembers feeling incredible relief at the news that, because a survey had revealed trauma among the entire first generation of teenage girls born into the Family, the law had been modified to exclude sex with children under 16.

At 10, Jones had already appeared with her mother in a video called Asian Angels, Volume 2, which was later confiscated by the government as child pornography. Her first coloring book was devoted to sex organs and practices. At 3, she found it boring since it only required one beige crayon. Jones writes that she often accompanied her mother on Flirty Fishing expeditions, a practice of luring new followers with sex, prescribed and promoted by her grandfather in his Mo Letters, writings distributed worldwide and simplified for children in a parallel series of publications called Kidz True Komics. In one Mo Letter, Jones explains, “there is a picture of a fisherman, who looks a bit like my father, holding a fishing rod with a long line and a large fishhook at the end. A naked woman is stabbed through the chest with his fishing hook. It’s her job to wiggle seductively and lure the Fish to bite the hook. This is Flirty Fishing, which the Family women have been practicing for nearly ten years now.”

This is the tip of the iceberg, but there’s also a lot more to this book than horrifying sex stuff. The author’s absorbing, meticulously detailed description of her early life with her eight siblings in Macau, and later episodes in Thailand, Hong Kong, the U.S. and Kazakhstan, recall both “The Glass Castle” and “Educated.” The extreme poverty, hard work and over-the-top physical punishment are balanced by a child’s-eye view of a fascinating, unfamiliar world.

Like Tara Westover, Jones was completely responsible for her own education. She found a copy of “The Secret Garden” in the trash along with other contraband brought in by a recruit. “The rich descriptions transport me,” she writes. “I live with each scene for days before I can sneak back and read the next one.” Blessedly, she had just finished the novel when her sister snatched it and their mother determined it had to be destroyed immediately because she said it was about witchcraft. But once Jones discovers the enchantment of fiction, there is no stopping her thirst for books and knowledge. She acquired a high school-level education completely on her own using a series of Mennonite home schooling booklets.

In the final chapters, we learn how she eventually broke free of her indoctrination, a process that took root during her undergraduate years at Georgetown University. She went on to law school and became a corporate attorney at the firm of Skadden, Arps. After a successful TEDx talk in 2018, she self-published “I Own Me: A Framework on Protecting and Respecting a Woman’s Body,” and continues to offer workshops and give presentations on body rights issues — decisions about health, sexuality and reproduction, in other words all the rights she didn’t have growing up.

Jones, now 44, asserts in her introduction, “Through all of this I never doubted that my parents loved me. They acted based on their sincerely held beliefs at the time, which have since changed dramatically.” She credits Alice Miller’s “The Drama of the Gifted Child” with helping her “understand what can happen with parents who physically beat, or even sexually abuse, their children. The book describes how people who think of themselves as ‘good’ can dole out violent spankings or other forms of child abuse without empathy.”

I think I need to reread that book, because this memoir has left me questioning humanity in some of the same ways as first-person accounts of the Holocaust. It is engrossing and well-crafted; it is shocking and at times, salacious; it is also seriously important.

Marion Winik a professor at the University of Baltimore, is the author of numerous books, including “First Comes Love,” “The Lunch-Box Chronicles” and most recently, “The Big Book of the Dead.”

Sex Cult Nun: Breaking Away from the Children of God, a Wild, Radical Religious Cult

By Faith Jones

William Morrow. 400 pages. $27.99