Check the calendar. It's 2016 still, right? Yet we're still debating antisemitism.

Nearly 80 years on from Kristallnacht, the infamous day when the outright persecution of Jews became commonplace in Nazi Germany, for some reason we are still discussing how to deal with antisemitism online, in person, even in major political parties.

It seems that in spite of its idiocy, we can't rid ourselves of the pernicious virus of antisemitism. Is it because, in fact, this ancient prejudice is somehow baked into Western culture?

When a debate on anti-Semitism is held on the fringe of the Labour Party conference, one might expect universal condemnation of this horrific racism aimed at a minority. Instead, rambling, incoherent bilge is spewed by an academic. Despite clear examples of antisemitism in Labour, the row within the party was described as "a monstrous soufflé of moral panic being whipped up". The speaker making this claim went on to say: "We need to ask about this soufflé, who the cooks are? Where's the kitchen? What are the implements? How's it been done?" 

What on earth is this supposed to mean? How can such absurd sentiments be considered part of public debate in the 21^st century?

When the Archbishop of Canterbury himself feels moved to write an essay on the evils of antisemitism, you know there's a problem. Justin Welby said antisemitism "is not a problem for one political party, one community or one sector of our society" but instead it "permeates and pervades all that it touches when it is swept under the carpet, denied and not confronted head-on".

Why are we still having this conversation? As Welby argues, the Church has to take much of the blame. "[The] habits of antisemitism have been burrowing into European and British culture for as long as we can remember," he argued, "It is a shameful truth that, through its theological teachings, the Church, which should have offered an antidote, compounded the spread of this virus."

In this, Welby puts his finger on the deep-seated root of the problem of antisemitism. From relatively early in the history of the Church, the treatment of Jews was chequered at best. In the early Church, many of the believers were of course Jewish. As the message spread, the number of ethnic Jews in the Church became fewer.

The idea of Jews as "Christ Killers" began. As Giles Fraser has argued, "Christianity bears primary responsibility for historic antisemitism. Few ideas can have been as poisonous as, and inspired more murderousness than, the idea that Jews were the Christ-killers."

By the time of St John Chrysostom in the 4th century, Christianity had gone from persecuted minority to being the official religion of the Roman Empire. Chrysostom spoke in uncompromising terminology about Jews.

Much has been written about his motivation for writing Eight Homilies Against The Jews. What is clear is that Chrysostom's sentiments were deeply unhelpful in ongoing relations. Michael Walzer argues: "Chrysostom... was such a violent opponent of 'the Jews' that earnest scholars have assumed that Judaism must have posed a clear and present danger to Christianity in his time. In fact... if Saint John feared the Jews, "it was because his theology had taught him to view other dangers in Jewish terms".

Chrysostom was not alone. Other Church Fathers showed hostility to Jews. Walzer says: "By the time of writers like Eusebius, Ambrose, and Augustine, the Jews had been... 'a twice-defeated people' – first militarily by the Romans and then religiously by the imperial establishment of Christianity."

This stain of the early Church was carried on through the Crusades, where Jews were killed by Christians, into the Reformation. Martin Luther's antisemitism was discussed by Mark Woods, in a piece for Christian Today earlier this year. He said, "the charges of antisemitism are absolutely true. In his book On the Jews and their Lies, he describes Jews as 'venomous beasts, vipers, disgusting scum' and 'devils incarnate'."

Luther went further than just writing, though. "He called for their them to be expelled from their homes, saying: 'Their private houses must be destroyed and devastated, they could be lodged in stables. Let the magistrates burn their synagogues and let whatever escapes be covered with sand and mud.'

A full history of the Church and antisemitism is more than I have space for here. But given the crucial role of Christianity in the development of Western thought, it is not hard to see why it continues to this day.

Into the modern era, via warning events such as the Dreyfus Affair, antisemitism reached its cataclysmic nadir during the Holocaust. Six million Jews were slaughtered by a supposedly Christian country.

Surely this horrific suffering endured by the Jewish people would finally shake western people, influenced still by Christian culture, even if they weren't Christians, from the grip of antisemitism.

Sadly, not yet. Christians continue to recycle the outrageous 'Christ killer' trope. Antisemitism is rife on social media – with a few clicks I have been able to find Nazis sympathizers happily posting away without censorship. It isn't just words. Antisemitic violence and killing continue to this day in Western Europe.

As we mark 80 years this week since the people of east London – Jews and gentiles – stood together proudly to oppose fascism at The Battle of Cable Street, now is the perfect time for us to renew our commitment to fighting antisemitism.

It seems appalling that we should need to restate this in 2016, yet here we are. There is no justification for antisemitism whatsoever. Christianity has been guilty of stoking the fires of hatred of Jews for far too long and we must have zero tolerance for this despicable attitude whenever it rears its head in our communities.

We must accept our share of the blame, make every physical and online space totally safe for Jewish people and clamp down heavily on those who perpetrate this despicable hatred. Anything less and we are complicit in an ancient and hateful crime.

Follow Andy Walton on Twitter @waltonandy