The pope has called together a coalition of faiths.

The fires of Smithfield and Madrid; the wars that tore apart Germany and Palestine and the Punjab – in the end, none of it was all that important. All that blood and death can be set aside. The acres of print and manuscript that defined the crucial importance of the incarnation and the precise nature of the Trinity, the arguments about the status of different revelations, the verbal and occasionally literal vitriol poured over the heads of theologians and clerics – all irrelevant.

From now on, between the faith communities of the world, it is what Tom Lehrer once called National Brotherhood Week. Only this time it's not – as in Lehrer's song – the Jews everyone can agree to hate, because parts of Judaism are joining this particular coalition; it's the queers.

Honestly, we should be proud. Ask, not for millennia of reparation for torture and murder in the name of faith, but just for the right to have committed relationships celebrated on an equal footing – and all the horrible old men who normally spend all their time disliking each other are suddenly in love. In a totally chaste way, of course.

A thousand years ago, popes called the warring principalities of Europe together for crusades against Islam. These days, Pope Benedict asks Orthodox bishops, and those rabbis inclined to co-operate and "the more significant representatives of Islam" – typical Vatican arrogance to have a view on which ones that is – to lobby against the growing tide of legislation to permit those churches that disagree with him to celebrate and bless same-sex partnerships. Of course, most of those other faiths regard his commitment to lifelong celibacy in the name of God as equally perverse, but in the name of brotherly oppurtunism are prepared to forget that too.

We might think the little token gesture of equal marriage trivial in the face of global warming, mass starvation, the banking crisis, the war of rival imperialisms – but the pope knows the truth. Equal marriage is, at the same time, the greatest threat there is and a symptom of what leads to all the others. Which, when it comes down to it, is the other thing that obsesses Benedict apart from other people's sex lives – a particular interpretation of post-modernism. Benedict is a theologian after all, and regards philosophies, especially philosophies he misunderstands, as being totally his business.

"Man calls his nature into question. From now on he is merely spirit and will." The fascinating thing is that Benedict, who is only too prepared to lay down absolute and unitary statements about human nature, projects that desire for certainty on to other people. Most progressives do not think anyone is "merely" anything – most of us believe that the essence of human nature is to be diverse, that identity is a braiding of strands. About the only people who think humanity should be will and spirit are the advocates of mind uploading, such as Martine Rothblatt, but even they have a more nuanced view than Benedict. He claims that revelation's view of human nature and sexuality is confirmed by biology, which is an astonishing claim for an intelligent person to make given the total diversity that honest empirical biology reveals. Perhaps catching infallibility has made him intellectually lazy.

Those of us who are trans – Benedict really has a problem with us, it seems – are not engaged in an attempt to confound nature, but to confirm it. Versions of trans identity have existed in many cultures and times – knowing this inspires me to be humble about the comparative privilege I experience rather than arrogant in my choice of it. Many people, some of them religious, have a nature that is essentially asexual and possibly celibate; if Benedict's sense of personal vocation to chastity is based in such a nature, good luck to him, but he should not try and dictate other people's lives.

He may have a Twitter account these days, but he doesn't seem to read other people's tweets, or listen to other points of view.

He advocates the family, yet seemed to have no problem with meeting Speaker Kadaga of Uganda, sponsor of a bill which mandates parents, on pain of imprisonment, to hand over LGBT children to imprisonment or death.

It is hard to know which is worse, the careless viciousness of what he is doing or its contemptible silliness.

• This article was amended on 1 January 2013. It originally stated that the pope gave an unconditional blessing to Speaker Kadaga of Uganda. In fact, no blessing was given at the meeting. This has now been corrected.