Ruth Powell, NCLS research director, says the initiative is based on new research from the US, which categorises Christians as evangelical according to what they believe rather than which denomination they belong to.

“We’re going to try it out in the 2016 NCLS survey and see how it works here in Australia,” Dr Powell said.

“We’re going to use exactly the same wording that they’ve used so we can compare the results. It’s a new opportunity and we should try it.”

The US report, by the National Association of Evangelicals (NAE) and Lifeway Research, identified evangelicals according to a strong belief in to four key statements:

• The Bible is the highest authority for what I believe.
• It is very important for me personally to encourage non-Christians to trust Jesus Christ as their Saviour.
• Jesus Christ’s death on the cross is the only sacrifice that could remove the penalty of my sin.
• Only those who trust in Jesus Christ alone as their Saviour receive God’s free gift of eternal salvation.

The NAE said the new research-driven creed aimed to improve the contested ways researchers quantify evangelicals in surveys.

Dr Powell pointed out that the definition is contested in the US because it is based on race and politics.

“So if you are African-American then they put you in a box based on your race and then they say all in this group vote in this way. They also have a very strong understanding of evangelicals as a voting bloc in America.

“Australia doesn’t have the same history and so we don’t have the same issue in terms of it being a contested understanding.”

However, she believes the new definition offers a third way of categorising Christians after their denomination and faith identity.

After asking individuals their denomination, the 2011 NCLS asked respondents to describe their faith identity.

They could choose two from the following list: Catholic, charismatic, evangelical, reformed, liberal, Lutheran, moderate, Pentecostal, progressive, traditionalist. The final category was: I do not identify with such descriptions.

Interestingly that last statement was the second most popular choice after Catholics.

“So there’s a big bunch of Catholics and then the the next biggest thing is ‘these labels don’t work for me.’ And the younger you are, the more likely you are to say ‘No, it’s not working for me. I’m Christian’.”

Only 1.7 per cent of Catholics identified as evangelical, although Dr Powell wonders if that may change if beliefs are measured.

However, she points out that all three ways of categorising will probably have flaws.

In the US survey, 41 per cent of self-identified evangelicals fell outside the new definition of evangelical belief, while 21 per cent of those who disavowed the evangelical label held beliefs that fell within the new definition.

“So it might have solved an issue to do with race in America but it may not be any better in Australia because none of them are going to be perfect,” Dr Powell said.

“So I think that’s important point for Australia, that you have to be very careful with the whole labelling of people. Be careful about how to box people. Be very careful with language and naming and making assumptions about people. Because things are shifting and moving.”