An expert on New Zealand's religious history says mainstream religions are losing members, a trend that's been apparent since the 1970s.
Figures from the 2013 Census show the number of people belonging to 'no religion' has jumped by 26% since the last census, to 1.6 million.
The figures, published by Statistics New Zealand, show Christians now make up less than half the population.
Associate professor of history at Massey University in Auckland Dr Peter Lineham told Morning Report that broad support in the past for the main Christian churches reflected a social structure which considered itself Christian but this is no longer the case.
"It's happening because the kind of religion that they practised was a low demand religion which was kind of mainstream and part of ordinary society."
He says Catholic congregations have grown more than other orthodox Christian religions but the overall numbers are also down.