The dragging of the nation's Catholic Bishops before an Anti-Discrimination Commission for distributing a benign pastoral letter on marriage is a deeply disturbing development for free speech and religious freedom in Australia.

It is a day that we at ACL hoped would not come. But we have been warning about it for years as political storm clouds of intolerance towards the message of Jesus in Australia have brewed.

I have provided some context to the legal action below.

But first, could I urge you to read the ACBC's pastoral letter, Don't Mess with Marriage, and as an act of solidarity with the timeless truth about marriage, encourage you to share it with all of your friends on social media and even by email?

We must tell our fellow Australians that basic teaching about marriage and family is considered illegal by some in our community and that they are prepared to use the law to shut down other peoples' views.

The Turnbull Government has promised that all Australians will have their say on marriage at a plebiscite after the 2016 election.

A plebiscite will not be fair if one side can use the big stick of the law to ban discussion on the key reasons for preserving marriage.

The use of the law to persecute same-sex marriage dissenters like florists and wedding cake makers is something that, in the minds of most Australians, happens “only in America”.

Despite opinion polls showing support for same-sex marriage, very few in Australia have seriously believed change will affect anyone else.

The bishops’ booklet was distributed nation-wide but in Tasmania, Archbishop Porteous, sent it home to parents in a sealed envelope with children enrolled in Catholic schools.

At the time public debate was running hot on the issue of same-sex marriage and rightly Porteous wanted to provide guidance to his flock on the church’s teaching.

Other bishops did the same.

It is an inoffensive booklet written in the style of a pastoral letter and is very respectful of same-sex attracted people.

Incensed, the leader of Australia’s gay marriage political movement, Rodney Croome, said the bishops had turned children into “couriers of prejudice”.  He urged people to complain to the Tasmania’s Anti-Discrimination Commissioner.

In response, a transgendered male-to-female candidate for the extreme left wing Greens political party, Martine Delany, lodged a complaint.

Commissioner Robin Banks ruled on Friday that not just Porteous, but the entire Australian Catholic Bishops’ Conference, has a case to answer.

They have 21 days to respond and it is highly like the matter will proceed to court.

That the largest church in Australia is under fire for doing what churches do, is such a shock to many Christians and other free speech loving people.

The gay lobby itself has spent years telling Australians that legalising same-sex marriage will not affect anyone else.

Sensing that this untruth may be exposed, media outlets campaigning for same-sex marriage, such as Fairfax’s The Age and Sydney Morning Herald,  have been silent about the case.

In recent years political activists for the gay lobby have had anti-discrimination laws amended to have sexual identity considered a protected attribute along with the likes of race or gender.

The trigger threshold is low in many of these statutes and in Tasmania, simply causing offense is enough to fall foul of the law.

Delany claims offense because the Bishop’s booklet allegedly implies same-sex attracted people are not “whole” humans and that gay marriage amounted to “messing with kids”.

In examining the context, it is clear Delany is clutching at straws. With regard to “whole” humans the bishops write of man-woman marriage:

“Their physical, spiritual, psychological and sexual differences show they are meant for each other, their union makes them whole, and through their union ‘in one flesh’ they together beget children who are ‘flesh of their flesh’.”

With regard to “messing with children”, the context not reported in the mainstream media is vital.

But sociological research, as well as the long experience of Church and society, attests to the importance for children of having, as far as possible, both a mother and father.  ‘Messing with marriage’, therefore, is also ‘messing with kids’. It is gravely unjust to them.

These are of course two of the most important arguments those seeking to preserve marriage wish to make in the public square.

Australia is to have a national people’s vote or plebiscite to finally settle the issue of same-sex marriage and same-sex marriage activists do not want these views heard by voters.

Australia’s new Prime Minister Malcolm Turnbull, who deposed Tony Abbott in a party room coup in September, has vowed to hold the plebiscite after next year’s federal election. This means the timing of the plebiscite is likely to be 2017.

The use of legal persecution to shut down one side of the debate does not auger well for a fair plebiscite campaign.