It will surprise some people reading this to hear that for over 10 years, in Brighton, I was a committed pro LGBT activist. I spoke at LGBT conferences. I wrote in the Times newspaper in favour of LGBT rights. Many of my closest friends were gay. But, as the years went by, I began to change my mind about the political arguments. Two things affected me in particular: facts I had been unaware of, and bullying.

One claim made in discussions about being gay was that it was not a choice. People were born gay. I remember the first time I discovered it was more complex than that. A lesbian friend whose hand I had held as she came out, skyped me from an American University Library. "Hey Gavin, it's great- I'm in love again." "Fantastic" I said, "who is she?" "No silly, it's a he." "But you've been gay for the last ten years." "Well I changed my mind when I met him."

Despite the public narrative, not everyone is born that way. There is a spectrum of choice, ranging from none, to a lot. And what is really strange is that it's very ok to describe people who move from straight to gay, but seriously forbidden to suggest that one can travel in the other direction too. Why is that?

Civil partnerships offered equal protection under the law. It's nobody else's business how long such relationships last. But the moment redefine what marriage is, you bring children into the discussion, and that ought to change the way we work out what our priorities are.

It's true straight people have not made a good job of stable relationships, and kids have suffered badly. But here as they say, is the thing; and I'm sorry to turn to statistics again. How long do straight marriages last? Not long enough obviously, but the figure is about 58% of traditional marriages last longer than 20 years.(Source: National Centre for Health Statistics, Centres for Disease Control and Prevention (2001). What do we know about same sex stability? The figures suggest about 5% of same-sex unions last longer than 20 years.(Source: 2003-2004 Gay/Lesbian Consumer Online Census) What do we know about stability and faithfulness? 85% of married women and 75.5% of married men report being faithful to their spouses. For homosexual males, the number is 4.5% (Sources: Laumann, The Social Organization of Sexuality, 216; McWhirter and Mattison, The Male Couple: How Relationships Develop (1984): 252-253; Wiederman, "Extramarital Sex," 170) And as for how one defines adultery for lesbians, the lawyers just gave up.

The evidence is that same sex relationships are much more fragile even than opposite sex ones- and if you are creating a framework to bring up children, this instability matters; but it is never talked about. As for 'religion', this discussion can be about religious belief, but it doesn't have to be; so I want to let a secular gay man I admire put the argument his way.

Paddy Manning, is a gay campaigner against same sex marriage. He also claims to be the last person criminalized under Ireland's anti-gay 'Offences against the Person Act 1861'. He says

"A same-sex relationship is different to a marriage because marriage is at its heart about children, and providing those children with their biological parents. Recognizing difference is not discrimination."

But what about gay couples acquiring children through surrogacy? Paddy claims "Surrogacy turns children into commodities, putting adult desires above the rights of children, having babies made to order and wombs to rent. We have seen in other countries how messy this can get. Where are the child's best interests in that? For me marriage is about children, with a mother and father, and not a way to measure or define adult relationships."

He goes further, and says that the bullying of those who do not agree terrifies him. "Bullying...family businesses are closed, professional careers shattered, Catholic schools forced to teach the Government vision of marriage. True equality recognises difference".

But it doesn't in this argument. Do you remember the Oregon bakers? They were not just fined $135,000 dollars in damages, and forced to 'retrain', but on this July 4th, also legally gagged from ever speaking in public about it. And it's not just them, and not just in Oregon.

This is about more than marriage. It's also about a form of cultural Marxism that enforces conformity. A lot is at stake.

The Rev. Canon Dr. Gavin Ashenden is Vicar of St Martin de Gouray in Jersey, the Channel Islands (just off the French Normandy coast). Trained at Oak Hill Theological College he became Senior Lecturer in the Psychology of Religion at Sussex University. He is a Chaplain to the Queen and Canon Theologian at Chichester Cathedral. As a broadcaster he has hosted a BBC Religion and Ethics show for 4 years (2008-2012) which had 100,000 listeners across the South East of England, and presented the BBC podcast on Religion and Ethics. He is the author of a number of books and essays on the Oxford Inklings.