On Tuesday, 16 August 2011, Christian lobbyists from across Australia will rally in Canberra to protest against allowing same-sex couples to marry.

This is an annual tradition that began in 2004 when John Howard promised a similar gathering in the Great Hall of Parliament House that he would forge ahead with his ban on same-sex marries. Nicola Roxon vowed Labor's support to the same crowd.

A lot has changed since then. Support for marriage equality has shifted from 36% to over 60%, with 75% of Australians thinking it is inevitable. And in the lead up to the ALP's National Conference, reform now has the support of almost every state Labor conference and leader.

This year's rally against equality - or "for marriage" as the organisers put it - will probably be the biggest and most heated ever. It will also be the most defensive.

Since marriage equality hit political centre-stage at the last election, the major narrative on the issue from groups like the Australian Christian Lobby (ACL) has been that Christians are victims of aggressive secularists, Greens and homosexuals who want to do away with religious freedoms.

When Doug Cameron compared the ban on same-sex marriage to apartheid, the ACL said he was calling defenders of traditional marriage racists.

When Kevin Rudd's sister, Loree Rudd, denounced marriage equality advocates as the global gay Gestapo, and an apology was called for from gay Holocaust victims, the ACL said Ms Rudd was being "abused and demonised."

When Queensland Premier Anna Bligh called the ACL "homophobic" for campaigning against an HIV prevention ad featuring a gay couple, ACL Chief of Staff Lyle Shelton called it an attack on Christian free speech:

"Over-sensitive homosexual activists and their uncivil friends ... are quick to jump from a great height with moral huffiness and personal abuse on anyone they perceive to step on their toes."

The Christian persecution narrative reached an absurd low when the entire "traditional marriage" team withdrew from a University of Tasmania debate on same-sex marriage in Launceston last month.

After Tasmanian Labor MP Brenton Best drew attention to the past anti-gay campaigning of State Liberal Michael Ferguson, the latter said he wouldn't debate because he feared "demonization" in such a "toxic environment" of anti-Christian hate.

ACL chief Jim Wallace and Australian Family Association spokesperson Terri Kelleher then withdrew in solidarity.

The university scrambled to find three replacements and the debate - which would have given Ferguson an excellent platform to exonerate himself from any accusations - went ahead without so much as a cross word the whole night.

This persecution narrative is nothing new. The American religious right and radical conservative movement play the victim card constantly.

Republican presidential nominees have even pledged to support a presidential commission to "investigate harassment of traditional marriage supporters."

The reason the persecution narrative has reached such a pitch because it is both politically convenient and culturally powerful.

At the political level, claiming victim status is a substitute for addressing the issue of marriage equality itself and diverts attention away from the weaknesses of the case against reform, chiefly its heavy reliance on the Bible.

It is also a way to divert attention from whose rights are actually under threat and who actually threatens them. As Andrew Badcock wrote to the Hobart Mercury after the Ferguson debate debacle:

"I haven't been to any rally that declared Christians are incapable of raising children or should not be able to marry, but I have had the misfortune to attend rallies where this was said of gay and lesbian people without any factual backing."

In particular, the Christian persecution narrative diverts attention away from the outrageous slurs against gay and lesbian people by some advocates on the religious right.

The ACL claimed its Queensland director Wendy Francis was the victim of "cyber bullying" during the HIV ad fracas mentioned above because someone called her "disgusting" on Facebook.

Compare that to Francis's statement when she was a Family First candidate comparing same-sex marriage to child abuse and you see how untethered from reality the Christian persecution narrative has become.

Most pointedly, the religious right's persecution narrative sets it up to (a) run scare campaigns about angry, litigious gay activists trampling religious freedoms from the altar to the classroom, and then (b) demand exemptions from whatever equality law is on the table to protect these freedoms.

The most recent example of this was a successful church demand for even broader exemptions from New York's anti-discrimination laws to ensure faith communities would not be forced to recognise same-sex couples once they were allowed to marry.

In Australia, churches are already free to turn away couples they dont want to marry, and free to refuse services to couples they don't recognise. But this won't stop some of them seeking even wider exemptions when marriage equality finally hits Parliament.

Beyond the political sphere, the cultural power of the persecution narrative lies deep in Christian history and theology.

To be persecuted is a sign of holiness. Christ Himself warned His followers they would be despised for His sake. Some Christians ask, if this sinful world is not persecuting me, am I really on the right path?

When perceived persecution comes, it is to be embraced as a sign that one's convictions are right and any wavering unthinkable. In this way the narrative goes around in a circle and becomes an easy way for religious leaders to corral their followers.

But what's easiest isn't always best. The persecution narrative doesn't win public debates.

As momentum for marriage equality grows and Australians ask to know more about the issues, the persecution narrative will look increasingly hollow and irrelevant.

Perhaps the religious right doesn't feel it can or should win wide popular support? Perhaps it feels that marshalling just enough adherents in just enough marginal seats is sufficient to hold the major parties hostage?

If so it has already lost. According to polls in the United States and Australia, the strength of feeling in the majority who support equality is quickly growing to match the strength of feeling in the minority opposed to it. When this happens, mega-churches in marginal seats will cease to matter.

The persecution narrative also risks inciting violence from those who feel under threat, however false that threat might be.

Already this year self-identified Christians have lashed out at marriage equality protesters in Adelaide and Brisbane. My fear is that as the debate heats up the religious right's overheated rhetoric may inspire more renegades to violence.

"Crying wolf" is another problem. When Christians in Australia or the United States claim persecution they devalue the very real persecution Christians suffer in other parts of the world, particularly in parts of Asia and the Middle East.

When the public gets the impression Christians are under attacks as much from Doug Cameron as from extremists in Iraq or India, it will cease to care about the latter.

Unfortunately, it seems there is nothing marriage equality advocates like myself can do to turn the Christian persecution narrative around.

Earlier this year, when Australian Marriage Equality pledged to respect the convictions and freedoms of those against equality, the pledge was dismissed by the ACL with examples of contrary behaviour, almost all from the United States.

We have to accept the persecution narrative will go on its merry way no matter how respectful we are to those who denounce us or paint us as bogeys. But this doesn't take away from the importance of continuing to model respect.

Among supporters of marriage equality there is naturally impatience, frustration, even anger. This will probably grow as resistance to change becomes ever more desperate and shrill.

But there is no place for such feelings in public debate, now or ever.

Whatever the religious right says, those involved in the movement for marriage equality must remain respectful of every shade of difference and dissension within the public debate.

Only when we show we are capable of the understanding and tolerance we have requested from the Australian people will we receive that understanding and tolerance in return.

Rodney Croome AM is Campaign Director for Australian Marriage Equality and an Honorary Lecturer in Sociology at the University of Tasmania.