There is no relationship this side of eternity quite like sacramental marriage. As Cardinal Robert Sarah reminds us in his new book on the priesthood, Christian marriage involves the continuous and complete self-giving in love of one person to another, a mirror perhaps of the love of the Persons of the Holy Trinity.

It is a sacred institution of lifelong and exclusive commitment between a man and a woman. It has many enemies but, if lived fully and faithfully, it is extremely rewarding.

So how should Catholics prepare for marriage? Faced with nearly 60 per cent of marriages ending in divorce within 15 years, the Spanish bishops, for instance, have just replaced 20 hours of preparation with a programme lasting three years.