Cory Bernardi, who split recently from the Liberal Party, is among those who have come to epitomise the idea of a Christian politician, arguing that Australia is and should remain Christian. One Nation's Pauline Hanson said repeatedly before last year's election that Australia was a "Christian country", although in her maiden speech as a senator she also noted that its government was secular. Bernardi cites the constitution as evidence that Australia is Christian and Nationals senator John Williams wants the Lord's Prayer to be part of the school system.

But there are many more Christian politicians I have been talking to who think very differently.

Recently elected West Australian Liberal MP Andrew Hastie, a former air services officer, says he gets "uncomfortable when people start calling Australia a Christian nation".

"I think the church has a distinct role in society but to extrapolate the church across the entire country and insist we are a Christian country is just wrong," he says.

A newly elected Labor member of the ACT's Legislative Assembly, former Uniting Church minister Gordon Ramsay, doesn't see Australia as Christian either.

"We have an extremely ancient people that predates Christianity and so that would be arrogant," he says, adding that modern-day Australia has a "healthy suspicion about religion".

Ramsay, a lawyer and the ACT's Attorney-General, sees similarities between the work of politicians and priests. He says both are about gathering wisdom. "It's not primarily about just what I believe, that I've got the truth and if you disagree with me, you're wrong. I think that good politics comes from good listening, good conversations. Good expressions of faith come from good listening, good understanding," he says.

Hastie, the federal member for Canning, attends a Christian Reformed church in the semi-rural Perth suburb of Baldivis. It meets in a high school, without what Hastie calls "institutional baggage".

"The trappings of power can be wherever you go," he says. "I've seen it in the military. I've seen it especially in the church."

Hastie, whose father is principal of the doctrinally conservative Presbyterian Theological College in Melbourne, bucked attempts by some in the media to define him as ultra-religious and, he says, a "crazy seven-day creationist". He says faith informs his world view but he is energised by lots of ideas and people. One of his favourite authors is Christopher Hitchens.

"Wherever the church and the state get too tight a weave, it diminishes the role of both. It's great to have a freer church where they can speak truth to power, and the state can legislate for everyone," he says.

"I am very conscious that I am a representative, first and foremost, of 150,000 people of many different backgrounds. When I make my case, I make it from a public policy perceptive and I try and use data, natural law, rather than appeal through religious authority, which is the straw man that people try and knock down."

Maria Vamvakinou, a Greek migrant of working-class roots, joined the Labor Party soon after Gough Whitlam was sacked in the mid-1970s. "I didn't single out the Labor Party because of the Greek Orthodox Church that I grew up in but, for me, it was the party that best reflected the values of the church," she says.

Serving her sixth term as the federal member for Calwell in Victoria, Vamvakinou also rejects the idea that Australia is a Christian nation. "We might have been perceived as a Christian country because of the nature of the people that came here. But to try and be one now in the 21st century would be counterproductive," she says. "We are a global community and we need to come to terms with our various faiths."

Vamvakinou serves one of the largest Muslim constituencies in Australia and a region with a significant Chaldean Catholic community, many from Iraq.

"I have tried to understand the inter-faith relationships and what they might mean for me who has always been an Orthodox Christian. If I have any challenges now, it is to try and understand what someone calls the Koran and I call the Bible, to treat them with the same reverence," she says.

"The Jesus story and Jesus as a historical figure has always fascinated me. A lot of my Muslim constituents will say they believe in Jesus and Mary as well. Their faith is as real to them as mine is to me."

Vamvakinou says when the Australian Christian Party stood candidates in Calwell in 2013, it tried to "infiltrate" the Chaldean Catholic community and "exploit their fear of Muslims and their experience within a Muslim dominated Middle East".

She says people of faith on the Labor side are more reluctant to talk about it than conservatives, to their detriment. "We don't make that connection. Lindsay Tanner used to. We had conversations with him and Kevin Rudd about this. I can tell you that one of the reasons my Iraqi Christians constituency came to Labor and stick with Labor is because of Kevin Rudd, as he articulated his Christian faith."

Her comments reflect Labor senator Sam Dastyari's concerns that progressives of faith in politics need to speak up to counter a rise in extremism. Dastyari says the conversation is often "dominated by the black-and-white views of what people thought someone's beliefs meant, rather than the more grey area of how they practised them". Labor, which has a number of progressive Muslim members of Parliament, has a big job to do.

The way the subject is reported is also an issue. Former NSW premier Kristina Keneally, a practising Catholic, is tired of journalists asking her how much her faith influenced her decision-making. "By the end of my [political] career, I started saying things like, 'Oh, 37 per cent.' It was a ridiculous question but, in my entire time in politics, nobody ever asked me 'what economist do you read' or 'who influences your economic thinking?'. Not one," she says.

Keneally, Hastie, Ramsay and Vamvakinou are critical of public discussion of Christianity (in fact, any religion) and politics. "Unsophisticated", says Keneally. "Crude", says Hastie. "Very shallow," laments Ramsay, who thinks people assume that to be religious is to be hard right and closed to new ideas.

"We are inheriting more and more the assumption from the United States that faith means conservative and so there is often little distinction between a person of Christian faith and a conservative evangelical. That's one framework of faith but it's certainly not the only one. We don't have in Australia, historically, a robust value of the place of progressive faith."

Keneally agrees. "The linkage between religion and political activity is often assumed to favour the right wing of politics. That frustrates me as a centre-left politician, largely because I view the Christian gospel from a social-justice perspective. Some of the strongest social justice statements that come out of the Catholic Bishops Conference have related to economic justice in Australia and welcoming asylum seekers. But that perspective is so rarely picked up and articulated by religiously affiliated political actors."

Ramsay isn't sure why. "I'm not sure whether conservatives in faith are more active in politics or whether they are more vocal or whether they are more covered. I have an inclination that they are just more covered," he says. Keneally thinks progressives are less likely to speak openly about their faith because they are scared of a "sneering and hysterical reaction from the media". There's a suspicion they have "loyalties outside of Australia, to the Pope or whoever; that was the dog whistle that permeated coverage of me".

Yet she says the people who met her were rarely suspicious. "If anything, people in my electorate liked and respected the fact that I believed in something, even if it wasn't the same thing they believed in or they understood, because I was upfront."

"When I said 'yes, I am Catholic', I would add that I am also a woman, also a mother, also an immigrant. All of these things shape how I view the world and the decisions I bring to bear. I am also a member of Parliament. I think Hastie has done a very good job, as a brand new MP thrust into the national spotlight with an attempt to stereotype him and typecast him. I don't agree with his policy positions, he and I would probably disagree on interpretations of scripture. But I admire the role he is playing."

Hastie doesn't buy the line from some conservative Christian lobbyists that Christians are persecuted in Australia but adds that animosity towards Christians often derives from a misunderstanding of the separation of church and state. "That idea is about the state not interfering with pre-political institutions like the church, or any other organisation for that matter. Our representative democracy is full of diversity. We have people of faith and no faith in the chamber. And that's a good thing; it reflects larger society. To try to push out people of faith would actually diminish the quality of our public policy.

"Also, look at Christ. He didn't seek to supplant the authorities of the day. He just asked for space in which to practise his beliefs and that of the church. It's a really important distinction."

In the 2011 census, 61 per cent of Australians identified as Christian, but only 8 per cent attended church weekly. Despite talk from Hanson and others about a Muslim threat, it's a tiny religion, accounting for just 2.2 per cent of the population, behind Buddhism with 2.5 per cent. It's not even the fastest-growing religion. That's Hinduism, with 1.3 per cent.

Jonathan Cole, a researcher with Charles Sturt University's Centre for Public and Contextual Theology, says the problem for progressive or moderate Christians is that conservative commentators make them invisible by only promoting Christians when it suits them. Centre-left commentators barely promote them at all.

"Look at the most prominent right-wing figures and commentators, such as Andrew Bolt and Alan Jones. They are not professing Christians but nor are they anti-religion, like many commentators on the left. They are happy to make common cause with conservative religious leaders. The left might have done a disservice to its cause by not creating enough space for Christian progressives among its ranks.

"One of the big challenges for progressive Christians is the tension between Christian history and progressive values; the church's historical support for oppressive regimes, its support of slavery and complicity in economic exploitation. There is a positive story to tell also, such as Martin Luther and anti-slavery campaigners, but the right are much more comfortable with Christian history; they own it.

"And the left tends to have an abuser problem; the abused become abusers. It preaches tolerance and equality. But if you belong to an oppressor class, and the main oppressor class today is deemed to be white, middle-class, straight and Christian, then you don't get the same tolerance because the left think you are guilty and don't deserve it. It doesn't apply tolerance fully. And this is where progressive Christians can help. They can instil the doctrine of forgiveness and reconciliation."

Vamvakinou doesn't see her modesty about her faith as a weakness. She says Australians need faith, of whatever kind, more than ever.

"We are in a very anti-religion, anti-church phase and a lot of our young people's negative views towards the church is to do with social issues at the moment," she says. "That's unfortunate because I think that human beings need to have faith, some sort of faith.

"To try to be a Christian country in the 21st century would be counterproductive. We are a global community and we need to come to terms with our various faiths."

Toni Hassan is a writer and former producer of radio programs with ABC Religion, and an adjunct research fellow at Charles Sturt University's Australian Centre for Christianity and Culture in Canberra.