The shifting of the category "no religion" to the top of the list of options on the census form and a campaign by the Atheism Association of Australia may have contributed.
Association president Kylie Sturgess explains, "The census 'no religion' campaign was encouraging people to intellectually engage with the census. If you're a Muslim, go right ahead, you put it down. Christian? Not a problem. But if you're someone who feels like you've fallen through the gaps, that you are no longer someone who is being recognised by an established religion, then maybe 'no religion,' which was a non-compulsory question, is the answer for you."
The data shows, while the numbers identifying with Christianity had an overall decline, it remains the top religion across all denominations.
More than half of all Australians still identify as Christian, and religious leaders say it does not necessarily mean people are losing faith.
The dean of Saint Andrew's Cathedral in Sydney, Kanishka Raffel, sees reasons to believe otherwise, "Sixty per cent of people say they identify with some religion. More than 50 per cent say that's Christianity. Which means, I think, that religion is important to a lot of people ... I think we could get very distorted impressions. Most people don't necessarily say a lot about their religion, and that might make you think, 'Oh, well, people aren't religious.' But if you ask them, you find (it's) something that's personally important to them."
Other faiths besides Christianity are growing. After Christianity, the top religions were:
Islam, which has grown from 2.1 per cent to 2.6 over 10 years.
Buddhism, which increased from 2.1 to 2.4 per cent .
And Hinduism, which grew from 0-point-7 (0.7) to 1.9 per cent.
Social researcher Ashley Fell says Hinduism showed the most marked gain, ""While Islam has overtaken Buddhism as Australia's second most popular religion, we are seeing that Hinduism is Australia's fastest-growing religion. And, of course, that is because we are seeing an increase in the number of migrants moving to Australia from India."
Nihal Agar of Hindu Council Australia belives that not many Hindus have opted for "No Religion" column. He says, "I hope that Hindus are not among these. If there are some, the number is very very small."
