I was a member of the The Family International for about 3 years though I didn't actually live with them. I used to go out with them "tracting" "postering" and "CDing" which were when we gave out gospel tract leaflets, would ask for a small donation for a A4 coloured poster with a message on the back about some Bible topic or go into small independent shops to see if they would like to stock a few of the CDs that The Family's musicians would churn out.
I also was on a sort of beginner's course which taught their view of the Bible and their beliefs, most of which were taken from "Mo Letters" which was what their leader David "Moses" Berg had written over the years. When he died in 1994 his common law wife Karen Zerby aka "Mama Maria" took over leadership with her new "husband" Peter Amsterdam. They also write letters with teachings in them and no aspect of a member's life can conflict with these teachings. For security reasons, no one except the most loyal leadership know where Zerby and Amsterdam live. All their literature is distributed through offices around the world. They are referred to as "Queen and King" or "Mama and Peter." Berg himself is called either "Grandpa" or "Dad."
They taught that if something was done "in love" then it was okay which included sleeping with multiple partners. In my time there (in one household where there were about 20 children and about 5 adults) about 7 of them had babies. Most of the girls were around 16 when they got pregnant as that's when they could legally have sex in the UK but one of the leaders was having her 8th child and she wasn't more than 35. The children are home schooled (but only til they are 16 when they are discouraged from seeking further education) and a younger girl will be assigned to look after the children of leaders as they are busy with admin and church business.
The leadership say that using contraception is okay but in several memos and letters I saw, members are encouraged to "go for the gold" which means not using it and letting "God decide" when you have kids which means there are loads more kids in the church than adults. However, they do not claim any kind of assistance or benefits from the governments of the countries they live in. Instead they generate their own incomes, mainly from musical concerts, "postering" and dance shows. The household I was associated with had a professional level dance group made up of young people who were "Bollywood" style performers. They travelled all over the country doing shows but always had to do as much work around the house and on the streets as those members who weren't dancers. All the people who book these dancers to do shows know is that they represent a "missionary" group. They also go "provisioning" which means getting food that is out of date or surplus for free. So they might end up eating nothing but fish for 3 weeks until they can get something else for free.
The reason I left was because of something called "The Loving Jesus Revolution." This was a doctrine that Zerby claimed had come to her from Jesus himself. It basically said that since the church is the "Bride of Christ" that when a person had sex or masturbated, he/she should imagine that they were doing that with Jesus. Male members were told to imagine that they were female when doing it and both sexes were told to ask Jesus to "fill them" with his "golden seeds." This doctrine was taught to all members from the age of 12 upwards.
That was the final nail in the coffin for me. That and the fact that when I started to have mental health problems they told me that I was being attacked by the Devil and needed to be prayed over daily. Many years ago, one of Berg's daughters, Faithy was "exorcised" of demons by beatings and sleep deprivation. I think I got off very lightly!
There are several websites and and a wiki thing about this group. Some are made by ex-members and are very interesting. Any Q's, just ask me.
In the year 76 or 77 I met some of your group at the Denver Airport during a layover on my way to a private school in Nebr. They tried to get me to donate my admission fee. It was right there in my front pocket. They told me how they were the Children of God or Family of God or something like that and kept pressuring me for cash. At first I just said I didn't have any cash and then one of the bright guys asked me what was in the envelope peeking out of my pocket. Being taught to NEVER lie I of course told what it was in the envelope. After a bit I got tired of the hassle and left.