In 2010, ‘Mama Maria’ ended the communal living mandate, effectively bringing The Family to an end. A David Berg website is still administered by The Family International, in which he is described as ‘the iconoclastic founder and spiritual leader of the non-traditional Christian movement known as The Family International.

‘David,’ the biography goes on, ‘retracted his more radical theological speculations regarding sexuality in the late 1980s, and these writings were officially renounced and removed from circulation.

‘His writings are permeated with the same love for God and passion for winning others to Christ that has motivated missionaries throughout the ages.’

But wait… Jones’s book is called Sex Cult Nun although as far as I can determine, she was never a nun, and has no intention of ever becoming one – she has a partner and would like to have children. There is a story behind that. In 2012 she was on a meditation retreat in a Buddhist monastery in Sri Lanka. 

‘There were two little nuns there, and they were at a plastic table, reading texts in the morning and then going round with a bucket of water cleaning, and I thought, wow, this looks really familiar… I was brought up like a nun – except there was a lot of sex involved! Grandpa even used to talk a lot about the “nuns of love”. And I thought, if ever I write a book I’m going to call it Sex Cult Nun.’

When she did come to write the book, she threw in the title, half intended as a joke. Her agent and editor both baulked at it, suggesting more dignified titles. The marketing department, however, didn’t like any of them. ‘And they said, “Well, the author had this idea…” and the marketing department said, “That’s the name!”’

She laughs heartily at that.

Sex Cult Nun by Faith Jones (HarperCollins, £16.99) is out on Thursday. Order your copy from the Telegraph Bookshop.

An exclusive extract from Sex Cult Nun by Faith Jones

Shortly after my father’s departure, we get word that someone From Grandpa’s house is coming to visit the Farm. 

Turns out, it’s Auntie Sara, who has been living in hiding with Grandpa. Boy, are we excited to meet her, someone we’ve read about in the comics and the Mo Letters for our whole lives. 

The fact that someone so important is coming to our faraway village feels like we’ve won the lottery. Auntie Sara arrives in secret, as the leaders always do. The first glimpse I have of her is at Devotions. 

There is nothing dramatic in her appearance. She’s a rather plain auntie with long, straight, thinning brown hair. She wears the same shapeless long dress as the other aunties. But there is nothing subtle about her impact. Her first night, she gathers all the teens together, except me. 

I’m not told about this meeting until I hear the shocked whispers from the teens afterward, and I’m cruelly disappointed that I missed out. Apparently, Auntie Sara did some kind of public sex demonstration with one of the teen boys. I couldn’t tell if what I’d heard was true, false, or mashed up in a game of broken telephone, but whatever it was, nothing like that had ever happened at our Farm before. 

There’s always been plenty of sex, but always behind closed doors. What does this mean for the rest of us? At teen Devotions the next morning, Auntie Sara explains that we are going to try out some experiments in how to raise Godly, dedicated, Family young people. 

“Though younger teens under sixteen can no longer have sex with the adults, you are still strongly encouraged to have sex with each other,” Auntie Sara tells us. “I’m going to implement an experimental  teen program here before introducing it in other countries.” 

She explains that teen girls are ready to get pregnant and marry at fifteen or sixteen, and in the big Homes they do. But many teens in the Family live in small Homes, with few in their age range. With Homes spread out around the world, the teens are in a tough  spot: they are taught to have sex, but they don’t have the chance to interact with many other Family members their age to find marriage partners. 

This is the real reason the leadership has decided to create teen training centers, where teens can learn to be better soldiers for Jesus and meet other Family teens to find marriage partners, settle down, and be so busy having babies that they won’t have time to get into trouble. Our Farm is going to be the grand experiment.