Diversity of human behaviour and variation of interpretation in matters deemed moral in character are anathema to religious authority the world over. Their lingua franca has more often stressed faith, doctrine and obedience. In any event, Thompson's otherwise worthy appeal for respect did not even last the duration of his own argument as he carped sarcastically "…full marks to whoever came up with the slogan 'marriage equality'." This too is consistent with the Christian playbook. A slick "Archbishop's Letter" circulated to the parents of every Catholic school student in the ACT in June, carried the message from the Catholic Bishops of Australia, under the title, "Don't Mess With Marriage". "We now face a struggle for the very soul of marriage" it stated. Thompson says opponents of change are being branded as "brain-dead" and "homophobes" in a disrespectful debate which is causing "other larger questions" to be thrown into stark relief: "Perhaps the most important of these is how we deal with whom we disagree." "In a society which genuinely prizes freedom and equality," he writes, "the chief principle of debate and argument must be persuasion rather than coercion."

Persuasion? For religions, whose centuries-old business model relies so fundamentally on the "persuasion" of children – others might have another name for it – this reference is bold. More striking again, is the depiction of these internally static power structures, run overwhelmingly by men as bulwarks against much that defines modernity (think science, feminism, personal freedom) as somehow outwardly committed to tolerance, diversity, and democracy. As leading Christians and other religious leaders complain about the current tenor of the public debate on same-sex marriage, they might reflect on the performance of their churches over all of the years leading up to it. They might consider the callous treatment meted out to homosexuals and others – real people in the real world for whom the churches have been at best, useless, and sometimes, central to entrenched discrimination. They might consider the callous treatment meted out to homosexuals and others – real people in the real world for whom the churches have been at best, useless, and sometimes, central to entrenched discrimination. This has been their undoing.

One of the triumphs of the Irish referendum in which 62 per cent of that mainly Catholic country voted for change, was the way the campaign leveraged the lived experience of homosexuals and their families. Its effective "ring-your-granny" campaign saw young gays appealing directly to family elders to end discrimination. And it saw those older and usually more conservative family members shift their opposition as they felt the effects of discrimination on their grandchildren – the ones they love. But now it's the churches that are complaining of rough treatment. One wonders where this new sensitivity to hurt feelings was as generations of young gay and lesbian people were marginalised, denied basic respect, and actively discriminated against? With some exceptions, the performance of Australia's major denominations in embracing difference, and showing compassion has been disappointing. When they weren't actively denying sexuality in their own clergy and demonising homosexuality as a satanic temptation to be resisted – with disastrous consequences for generations of children – these bedrock "institutions" routinely sat idly by as discrimination, and bullying continued.

When popular discourse depicted gays as faggots, poofters, queens and dykes, most church leaders said little or nothing. It wasn't churches who drove change and increased tolerance. Yet now, as they weather a degree of understandable pent-up anger, they complain about being "shouted" at. As almost every teenager growing up in egalitarian Australia would know from bitter personal experience, being gay or transgender, has never been the path of least resistance. Yet the churches offered little refuge. Suicide rates and the incidence of self-harming and destructive behaviour attest to the extreme isolation experienced by adolescents who did not fit God's mandated template. This is the moral score-card of organised religion. Now, the defenders of "traditional" marriage are styling themselves as the new victims. They say they are being called names, stereotyped, discriminated against. As a religious scholar, Thompson's defence of the status quo is unsurprising. Yet it should be seen for what it is: the latest in a series of unconvincing cavitations created by institutions that are fast losing the moral authority they seek to exercise.

Such desperation is everywhere. Julia Gillard's belated conversion will have convinced few. But that is still probably greater than the number of people who bought her bizarre logic in cravenly opposing marriage equality while in office. The same absence of conviction is also obvious in the sudden recourse to the shining virtue of democracy via a plebiscite – something the Prime Minister and other trenchant opponents scoffed at just months ago. It's politics. And it's religion. And it's the opposite of progress. Mark Kenny is Fairfax Media's chief political correspondent.