But sect members are not completely divorced from "worldly" life. In fact, day-to-day life in the Exclusive Brethren does include the occasional use of modern technology. When I met four members of the sect at The TES this week, one even carried a laptop computer. He used it to show a film portraying the life of a Brethren family from New Zealand.
"In exceptional circumstances, where it is not for profit or gain, we will use such technology, but we do not employ it in our homes or businesses," said Graham Reiner, a Brethren member from south London.
The Brethren also runs its own website - www.theexclusivebrethren.com - even though members are barred from using the internet. Members say it was set up to spread the truth about the Brethren after they took legal action against two websites which they believed had libelled the sect.
Despite their concerns about modern technology, the Brethren say that selected computer programs are used by disabled and special needs pupils in their schools, although links to the internet are removed.
Newspapers are also widely read. When we met, one member carried a copy of The Times. Others said they bought a daily paper, and that the Financial Times was used in business studies lessons.