There is nothing new under the sun. Yet some depressing patterns repeat with such alarming regularity that one wonders if some people missed the memo.

On this occasion, I'm talking about the ridiculous propensity of conservative Christians to brand the LGBT community as 'Nazis', 'fascists' or some other permutation.

This week's example comes courtesy of Margaret Court, one of the most successful tennis players of all time and a Pentecostal pastor.

Just days after saying she wouldn't fly with Quantas because of the airline's pro-LGBT stance, she likened gay activists to dictators. 'That's what Hitler did. That's what communism did – get in the minds of the children,' she said. 'There's a whole plot in our nation and in the nations of the world to get in the minds of the children.'

The 74-year-old Australian is just the latest Christian leader to make a comparison between gay activists and the Nazis.

Bryan Fischer is a radio host for the American Family Association. 'They are Nazis,' he said in 2011. 'Homosexual activists, when it comes to freedom of speech, are Nazis. When it comes to freedom of religion, they are Nazis.'

Fischer isn't here just equating gay activists with the Nazis but actually saying they ARE Nazis. 'Do not be under any illusions about what homosexual activists will do with your freedoms and your religion if they have the opportunity,' he said. 'They'll do the same thing to you that the Nazis did to their opponents in Nazi Germany.'

In Russia this week, the Patriarch of the Orthodox Church – a hugely influential figure – is reported to have compared gay marriage to Nazism.

The UK has not escaped this deeply depressing trope either. Alan Craig, at one time the leader of the Christian People's Alliance and later a UKIP supporter, wrote a blog with the title, 'Confronting The Gaystapo.'

In it he said, 'the UK's victorious Gaystapo are now on a roll. Their gay-rights storm troopers take no prisoners as they annex our wider culture,' suggesting various groups of ordinary British people 'find themselves crushed under the pink jack-boot'.

Addressing the introduction of same sex marriage in the UK he wrote, 'But it's only 1938 and Nazi expansionist ambitions are far from sated. Flattered by appeasers and feted by the political class, the Oberkommandos from Stonewall and OutRage! have expansive goals for cultural hegemony and have long wanted to march on the next territory.'

The list could go on, but it's time to ask why this is such a counterproductive and offensive strategy. Let's get to the most obvious point first of all. The Nazis actually persecuted and murdered homosexuals. 100,000 were arrested and between 5,000 and 15,000 were sent to concentration camps.

To then compare gay activists to Nazis is a move so callous and insensitive that those making it should be deeply ashamed of themselves. Nazis killed gay people simply for being gay. To suggest contemporary gay people are Nazis puts these extremist statements well beyond the pale.

There are several other reasons why it's got to stop immediately, though.

Firstly, using the term 'Nazi' or related terms, as an insult is an attempt to close down discussion. Online, there is a long-established convention known as Godwin's Law. It basically states that if you bring the Nazis into your argument you've already lost, because it shows you can't make the point without resorting to extreme rhetoric.

Secondly, by describing the 'gay agenda' as equivalent to Nazism, there is no chance of a decent public debate around LGBT issues. There are genuine questions about what and when children should be taught about sexuality, for example. Christians will be unable to take part in that debate in a constructive and calm way if their co-religionists are busy ranting about Nazis – we'll be written off.

A third reason it's so unhelpful for the Nazis to be invoked in this debate is that it provokes an 'arms race' in which the insults come back from others in an extreme form. 'Evangelicals are The American Taliban,' said one recent article. Really? Is that true? Obviously not, however much you dislike them.

Yet, we can't call out this inflammatory rhetoric for what it is if we're doing exactly the same thing. In a world so divided, where actual religious persecution sees Christians and other minorities being targeted on a daily basis, it's incumbent on us to be responsible with our language.

So, please, however much you disagree with someone, and however wrong you think they are, unless they are literally a Nazi, be very, very careful before you deploy that deeply loaded word. You may think you're being edgy and combative, but you're not. You're making things worse for everyone.

Follow Andy Walton on Twitter @waltonandy