Malcolm Muggeridge used to say that sex is the mysticism of materialism; and I think he was right. Sex is probably the closest the material can get to the numinous. That is probably why mainline churches are so obsessed with sex: having lost their faith, it is all that is left.

None of this explains why a celibate monk would choose to write a book about sex, though:

A Polish priest has raised eyebrows with the publication of sex manual that advises couples to have a ‘saucy and fantasy packed’ love life.

In Sex as you don’t know it: For married couples who love God, which has been described in Poland as a “Catholic Kama Sutra”, Father Ksawery Knotz goes against the traditional attitudes of the church towards sex.

“I compare sex to a football match,” he said. “There are rules, for example you can’t foul or kick the ball out. However, what goes on on the pitch may involve matches of different standards, different leagues. There can be fantastic matches as well as boring ones.”

While some Poles have questioned the competency of a celibate monk who lives in monastery to write about sex, Father Knotz remains unfazed.
He said that his experience comes from listening to married couples talk about sex, and he has run a website giving sexual advice in both Polish and English for almost a year.

Is this the equivalent of a vegetarian waxing eloquent on specific cuts of meat or a teetotaller dwelling on the joys of wine tasting; well, yes, probably. The ineptitude due to inexperience give-away is the comparison to a football match.