Of all European countries, you might have thought, France would have taken gay marriage in its stride. Is France not where free-living Britons, gay and straight alike, traditionally found refuge from their own more censorious compatriots? Yet same-sex marriage has gained readier acceptance in the UK.
The day after President Francois Hollande signed France's gay marriage bill into law, more than 150,000 people thronged the streets of Paris in a vociferous red, white and blue protest. The week before, far-right historian Dominique Venner had shot himself at the altar of Notre Dame cathedral, after condemning gay marriage on his blog.
None of this stopped the country's first gay wedding. On Wednesday 40-year-old Vincent Autin and 30-year-old Bruno Boileau were joined in matrimony by the socialist mayor of Montpellier.
The President was there. The ceremony was shown live on French television. The happy couple kissed; the champagne flowed, as did the tears (of joy). But the gendarmes were out to ensure security and many mayors say they will refuse to officiate at gay weddings.
The ferocity of the gay marriage controversy says says that France is a more conservative, more Catholic, country than is often realised. The temporal power of the church may have been destroyed by the revolution, along with its ancient monasteries and estates, but its spiritual power has endured.
A glance back across the Channel might even suggest that the constitutional separation of church and state may have kept the church in France stronger than it would otherwise have been.
The church's influence flies for the most part below the social radar. God-fearing Catholics follow their upbringing and current Vatican teaching in regarding same-sex relationships as wrong. They make exceptions for friends and family, but when it comes to marriage, they share the belief that the institution unites a man and a woman.
Opposition to gay marriage in France, however, highlights a more general point. The way in which religion has become embroiled in the gay marriage debate and gay marriage in the religion debate has been profoundly unhelpful to both.
A telling detail in some reports of the Autin-Boileau marriage was that they walked down the aisle together. That phrase seemed to betray an instinct, perhaps even a desire, to conflate this civil occasion with a religious one. But this was not a church wedding; it was a civil ceremony of the sort that takes place every day across France.
Here, as in the other dozen or so countries where gay marriage is legal, it is civil law, not canonical law, in which gay marriage is enshrined. It is the state, not the church, that decrees that gay couples should have the possibility of the same legal rights as those enjoyed by married heterosexual couples. They include rights related to property, inheritance and tax, as well as social rights, such as the right to adopt children.
In many countries, France included, couples must go through a civil ceremony in addition to the religious one in order to be legally married. But it is the religious rite that is remembered, and celebrated, as the real marriage.
That the words wedding and marriage are used equally for church and civil ceremonies only introduces further confusion. The right for gay people to marry seems to have lodged in the public consciousness less as the right to equality with straight couples before the law (which it is), than as the right to marry in church (which it is not). Unfortunately, it is far too late to change the terminology.
I entirely understand why many gay people, not only religious believers, insist that they will not enjoy full equality until they can marry in a religious ceremony on the same terms as straight couples.
The Anglican Church tore itself apart for the best part of 30 years over women priests and is still not reconciled; it is going through similar spasms over female and gay bishops. Same-sex marriage is causing new ructions, with even the new Archbishop of Canterbury apparently unsure what he thinks. The Roman Catholic Church, like the Eastern Orthodox churches, has barely started down this liberalising route.
For many believers, gender is fundamental to their faith. And while many of the faithful have adapted their views to the times, many others regard certain tenets, such as the nature of the priesthood or of marriage, as immutable. The Anglican Church may have avoided schism in name, but a de facto schism exists not just on gay marriage, but on the place of women and homosexuals generally and the state cannot be expected to change this.
In terms of secular rights, homosexuals have won the battle on both sides of the Channel. That is a huge advance, and one that the doctrinal agony of the churches should not be allowed to diminish.