The Presbyterian Church is considering refusing to participate in secular marriage if gay marriage is allowed to go ahead.
Last week, the NSW arm of the Presbyterian Church, which is the fourth largest religious group in Australia, decided to ask its national branch to take the steps necessary to withdraw from the Marriage Act entirely if same sex unions are no longer banned by law.
John McClean, the convenor of the Gospel, Society and Culture Committee of the NSW Presbyterian Church, said there was a growing gap between the classic Christian view of marriage and the attitude of Australian society.
"Most people do not think that sex is only for marriage and the vast majority of couples in Australia who marry live together first," he wrote in an opinion piece for Fairfax Media published on Monday evening. "Many Australians are not convinced that marriage should be for life."
When asked why it was gay marriage, rather than no-fault divorce or pre-marital sex, that had prompted the church to consider refusing to participate in marriage laws, he said he was not around in 1975 when no-fault divorce was introduced.
"I do think there are a lot of Christian people who see the same-sex marriage issue as the big issue," he said. "For me, it's really one more step along what has really been a long process over the past few decades."
He said if the marriage act was changed it would have no effect on Presbyterians, as they followed the teachings of Jesus on marriage, rather than secular laws, "but we would think that leaving the Marriage Act is a way to make that position as clear as possible".
Last month, Canberra couple Nick and Sarah Jensen faced a community backlash after Mr Jensen announced the couple would divorce if same-sex marriage was allowed.
More than 187,000 thousand Australians have since replied to a Facebook event set up to celebrate their divorce in the event of a law change.
Dr McClean said the step taken by the NSW Presbyterian Church was not intended to isolate or upset gay Australians.
"What we are doing here is about our direction of the Church and our relationship with the marriage act, it's not really a statement that is directed at the gay community," he said.
He said despite the fact that Jesus had not specifically spoken about the issue of gay marriage, Jesus' views were clear when asked about the issue of men abandoning their wives. Jesus had stated: "Have you not read that He who made them at the beginning 'made them male and female" - and Jesus took a consistent approach to that issue, Dr McClean said.
"It's not that classical Christianity just arbitrarily picks what continues to apply and what doesn't, there is a pattern that you can see in the Bible," Dr McClean said.
If the Presbyterian Church did abandon the Marriage Act it would continue to celebrate marriages, but in a way that wasn't recognised by Australian law, he said.
According to the most recent Census, "Presbyterian and Reformed" is the fourth most common religious group in Australia, covering nearly 3 per cent of the population. About 25 per cent of people identify as Catholic and 22 per cent as no religion.
However, in the 2011 Census the Presbyterian Church fell out of the top five religious groupings in NSW, replaced by Islam.
