While the majority of Catholics who know about their Church find The Da Vinci Code a preposterous book, many do consider Opus Dei if not threatening, then at least odd. Certainly, for people like me, whom Opus Dei attempted to recruit at the age of 18 through the guise of encouraging me to attend A-level seminars at a "study centre", the organisation has always left a rather sour taste.
For too long it had a reputation as divisive and elitist, even as a dubious cult which encouraged impressionable young people to follow its strict, ultra-traditional, right-wing ways. It wasn't helped by connections to Spain's General Franco, and its members' reputed liking for discipline - of the sound-thrashing variety.
In recent years, Opus Dei has made a clear attempt to enlighten people about its activities. Now, with John Allen's comprehensive account of the organisation, far more has been revealed than ever before. Allen, highly respected Vatican correspondent for the National Catholic Reporter, focuses on some of the most controversial aspects of the organisation, from its treatment of women to its recruitment and its money, as well as offering an account of its origins and the spread of its influence.
Opus Dei was founded in Spain by Josemaria Escrivá, a priest who called on priests and laity to dedicate their lives and work to God. Whether it is as a bus-driver or a CEO, an Opus Dei member, he says, can become more of a child of God by doing their job well and making Christ the centre of their life. Members, Allen explains, commit themselves fully to this life by being "numeraries" - full-time celibate members who live in Opus Dei centres - or "super-numeraries", who live in their own homes. Their dedication to God, through Mass-going, reading and prayer, is highly impressive. These are serious people, whose intimacy with God illuminates all they do.
Allen also emphasises how forcefully founder Escrivá, who was canonised in 2002, just 27 years after his death, stressed that the laity and their spiritual development should be important in the Church. In the mid-20th century, the Catholic church was particularly clerical, and this view was unusual at the time. It was later was endorsed by the Second Vatican Council.
That said, one wonders why anyone needs Opus Dei. After all, given it is perfectly possible to have such a dedicated prayer-life without it, and if its view of the laity, as Allen argues, merely reflects today's conventions, why bother with Opus? One senses from his interviews that it appeals to a kind of intense individual who is needy, wanting the support of an organisation that insists on obedience.
That leaves all those other issues, which many sympathisers, and Allen, think outsiders focus on too much: the money, the attitude to women, secretiveness and mortification. Allen argues that Opus Dei really doesn't have much cash, yet he still estimates it receives around $51m. a year, and in America alone it controls around $344m. in assets.
While women members are encouraged to have theological training, married ones are expected to be good Catholics with large families, and some unmarried ones are expected to have servile roles in Opus Dei properties.
Then there is the secrecy. The late Cardinal Basil Hume was suspicious of its methods, but Opus seems to have done its best to be more open today. Yet the brouhaha surrounding Education Secretary Ruth Kelly was typical of both the organisation, and its members' reluctance to admit or deny who is involved.
On all these issues, Allen seems suprisingly sympathetic, as he does on mortification. But here the explanations just won't wash. Flagellation and wearing spikes on the thigh are really pretty odd in the 21st century. As a feature in GQ rightly put it: What's with the whips?
Allen has produced an exhaustive work, packed with endless facts. The most startling of all, given all the fuss about Opus Dei, is that it has just 85,000 members, and only 500 in Britain. Perhaps it's time that we all, Dan Brown included, just calmed down.
Catherine Pepinster is the editor of 'The Tablet', the Catholic weeklyReuse content