Auschwitz-Birkenau, Poland: "We do not want our past to be our children's future."

Choking with tears, standing before the "death gate" of Birkenau, Auschwitz survivor Roman Kent forced himself to continue.

"That is the key to our resistance. We survivors do not want our past to be our children's future."

There was anger as well as grief and mourning at a freezing, snowing Auschwitz on Tuesday, as hundreds of survivors, and political and religious leaders gathered for the 70th anniversary of the liberation of the infamous death camp.

Ronald Lauder, president of the World Jewish Congress, told the gathering that after anti-Semitic marches on the streets of Europe, attacks on synagogues and Jewish businesses, and the siege at a kosher supermarket in Paris, "it looks more like 1933 than 2015".

A "new storm of anti-Semitism" was sweeping through Europe, he said. "An awful wave of hatred has descended on Earth once again."

Schools must teach tolerance, houses of worship must teach love and countries must make hate a crime, he demanded.

Otherwise "the tragedy of this terrible place will darken the world again."

This was partly, as always, a ceremony for the dead, a renewed vow of remembrance to a million murdered souls.

But the 70th anniversary of the liberation of Auschwitz on Tuesday also had an air of a farewell – that living memory was being handed on to a new generation as a solemn, urgent obligation.

Ten years ago, 1500 Auschwitz survivors attended the 60th anniversary ceremony. This year, organisers estimated about 300 were alive and able to make the journey.

Even as his body becomes more frail, Mr Kent wanted to pass a moral, determined strength to new generations.

To the applause and tears of the gathering, he insisted that they live up to the demands of the legacy of the Holocaust.

"For me, to forget the horrific experiences in concentration camps even for one moment is impossible," he said.

"Witnessing the atrocities committed at the entrance gate to Auschwitz was more than enough to keep me awake at night until the end of time."

He could never erase the sight of living "human skeletons", the smell of burning flesh from the blue smoke that came from the chimneys of the crematoriums, the sound of the "heartbreaking weep of children torn from their mothers' arms by the brutal action of torturers".

"If we were to forget, the conscience of mankind would be buried alongside the victims," he said.

"To remember is not enough. Deeds are crucial. We all must make clear that hate is never right.

"Never be a spectator. Never, ever be a bystander."

Former prisoner Halina Birenbaum remembered, amid the agony and mud, that one day as a 14-year-old she had worried she may "never experience a true love's kiss".

"Auschwitz lingers in evil and is reborn in anti-Semitism and racism," she said.

Polish President Bronislaw Komorowski told the gathering they were standing "where our civilisation went down … in the place that reminds us of the murderous Nazi ideology that undermined the pillars of the world."

Before the ceremony Dr Piotr Cywinski, director of the Auschwitz-Birkenau State Museum, said it was an honour and a privilege to host the survivors.

"It is a very, very big deal for them coming here, not only because of their age but the emotions, the emotions of the camp are coming back when they see the [buildings]," he said.

"We have to say it clearly: it is the last big anniversary that we can commemorate with a numerous group of survivors. Until now, it has been them who taught us how to look at the tragedy of the victims of the Third Reich.

"Soon it will not be the witnesses of those years, but us, the post-war generations, who will pass this horrible knowledge and the crushing conclusions that result from it."

The survivors came, those that could, to weep under the gates of Auschwitz I with their 'Arbeit macht frei', 'work makes you free', logo.

They came to lay candles at the "wall of death" where so many prisoners were stripped, herded together and shot, next door to the building where the first experiments with Zyklon B led to the development of the gas chambers.

And then they came to the ceremony before the "gate of death" into Auschwitz-Birkenau, the sprawling, ruined camp that none of its hundreds of thousands of inmates were intended to survive, and most didn't.

 

On January 27, 1945, two Soviet rifle divisions liberated the Auschwitz camps. By then, only 7000 prisoners remained. More than a million had been killed here, and thousands of survivors had been forced into "death marches" by the retreating Nazis.

The ceremony ended with El Male Rachamim, the prayer for the souls of the dead, sung by Auschwitz survivor David Wisnia.

As an early arrival at the camp, he and his fellow captives were forced to build the crematoriums where so many Jews would later be gassed.

"I will never forget listening to the singing [of inmates] on the way to the crematorium," Mr Wisnia said. "We did not come there to live, we came there to die."

Early on Monday morning, in a hotel around the corner from the Auschwitz-Birkenau camp site, Mr Wisnia suddenly woke up, to find the curtain drawn between him and his past torn away.

"I had a horrible dream," he said the next day. "I woke up and looked out the window and sort of thought I was back in Birkenau and Cell Block 14 where I started from in 1942.

"It's impossible to describe this feeling. This is the first time this happened to me in the last 70 years. I had managed to separate myself, divorce myself from that."

He says the Holocaust gave the human race "an idea of what we can be".

"We can either be good, or we can be bad. We have been given a choice. So choose life."

Australia's Assistant Treasurer, Josh Frydenberg, was representing his country – and also his family - at Tuesday's ceremony, laying a candle on the Auschwitz memorial. His great-aunt and great-uncle survived the camp, but many other relatives including his great-grandparents were killed here.

He said it was "harrowing" to look at the buildings and walk among them, and see the crematoriums, piles of shoes and glasses and hair retained from victims.

"It's chilling to think so many innocent people lost their lives here. It was killing on an industrial scale. It's just incredible to think such brutality found its way into a civilised society.

"We have a responsibility to make sure the memories of the victims are honoured and that nothing like this ever happens again.

"We have a duty as a civilised, tolerant nation to ensure that nothing like the intolerance, anti-semitism and brutality of the Nazi war machine ever comes back."

At the end of the ceremony, Mr Frydenberg walked a kilometre along the old train tracks to lay a candle at the memorial to the dead.

"It was a very moving event," he said. "In the dark and cold, walking along that train line - it was incredible."

Mr Frydenberg was accompanied by Australian ambassador to Poland Jean Dunn.

Another Australian, Greg Masel, director-general of Israeli Fundraising Foundation Keren Hayesod, also attended – partly as a representative for Australian businessman Frank Lowy, whose father was murdered at the camp and who has contributed large sums to a fund for its preservation.

Mr Komorowski thanked all donors to the museum, saying they were preserving the "conscience of humanity".