The Uniting Church is facing growing unrest as conservative factions push for it to reverse its decision to allow ministers to perform same-sex marriages.

Key points: The Uniting Church has allowed ministers to choose whether to conduct same-sex marriages since 2018

The Uniting Church has allowed ministers to choose whether to conduct same-sex marriages since 2018 Conservative churches have begun separating themselves from the main assembly

Conservative churches have begun separating themselves from the main assembly Members are divided about whether they are following scripture

Multiple conservative movements have been gaining force since the church last year gave ministers the right to perform the ceremonies.

Some are threatening to take control of church property and finances — positioning themselves as alternatives to the main Uniting Church in Australia assembly.

One of the movements is the Assembly of Confessing Congregations.

Reverend Hedley Fihaki says same-sex marriage goes against scripture. ( Supplied )

"The main issue is an issue of faith — what is the Gospel? Same-sex marriage is just one of those issues," the congregation's chair Reverend Hedley Fihaki said.

"I think there's a division not just between the Assembly of Confessing Congregations and the Uniting Church, but [also] … between evangelicals as a whole and the Uniting Church."

Dr Fihaki said the issue had created an "irreparable rift", causing members to leave the church.

He said many ministers and congregations had also decided to join the assembly, which was set up in 2006.

"The new decisions that have been made by the [Uniting Church] seem to suggest that it can be other lords, other sexual practices and still be okay," he said.

"We are saying no, that's not right, according to our understanding of scripture and the basis of union."

In a statement in March, the assembly encouraged its members to take ownership of matters of finance, signage and anything else which advances their "unity, life and witness".

It also suggested members develop their own relationship with other networks, denominational churches and leaders.

In doing so, members claim they have felt the force of church leadership.

The Gold Coast's Newlife Church has removed the Uniting Church logo from its signage. ( Facebook )

Dr Fihaki wrote to Uniting Church in Australia president Deidre Palmer in February to request no further attempt be made to "bully and ostracise" Assembly of Confessing Congregations members and leaders.

"The Uniting Church wants to assert its authority over us, when we're simply trying our best to maintain our integrity in the way we live and practise our Christian faith," he said.

"I think the church is too quick to throw regulations at us, without actually sitting down and trying to understand where we are coming from."

Truly united?

The Uniting Church faces pressure on the issue from multiple conservative factions.

Eight ministers last year penned an open letter — entitled "Standing Firm by Stepping Aside" — rejecting same-sex marriage and vowing to protest until the church reversed its decision.

Some congregations, such as the Gold Coast megachurch Newlife Church, have begun separating themselves by removing the Uniting Church name from their signage.

Reverend Stuart Cameron signed the letter.

He also oversees Newlife and announced the creation of the "Propel Network" which holds "similar priorities" to the Assembly of Confessing Congregations.

The open letter also suggested the creation of a "non-geographic presbytery" which would transcend formal Uniting Church governance to provide a "safe space" for members to pursue their orthodox beliefs.

The creation of a non-geographic presbytery in South Australia called "Generate" will be decided at a meeting of the state synod and presbytery in June.

One entire South Australian congregation is considering returning to its Presbyterian roots.

The Uniting Church was established in 1977 as a union of Methodist, Presbyterian and Congregationalist churches. ( ABC News: Eugene Boisvert )

Monash University sociology expert Gary Bouma said it was possible the groups could eventually split from the Uniting Church.

"When these divisions get to be very heated, there become those who organise themselves in different kinds of ways," Professor Bouma said.

"Whether [the groups in question] are seeking to establish a new church by themselves, as sometimes happens, or just to have an organised group to represent their view, I'm not sure.

"Certainly, this appears to be a group stepping towards a separate organisation. And that's happened many, many times before."

Reverend Roger Munson conducts a same-sex marriage in the ACT in 2013. The law was quickly struck down. ( AAP: Alan Porritt )

Fighting taking a toll on members

Openly bisexual minister Avril Hannah-Jones completed a doctorate on sexuality within the Uniting Church and said debate on the issue had existed for as long as she could remember.

"The Uniting Church has always been known to be the weird church that talks about sexuality and then welcomes gay and lesbian people," she said.

"I will feel very sad if people think this is the point at which they can no longer be part of the Uniting Church.

"I think it will be devastating, but I'm sure they'll be able to find homes in other churches."

Reverend Avril Hannah-Jones says the discussion about same-sex marriage has been hurtful. ( Love Makes A Way )

Dr Hannah-Jones said she was proud of Uniting Church leadership for embracing a progressive standpoint.

"I think the leadership has a really difficult job to balance the different opinions … I would like it to be more proactive about issues of harassment, but I understand that's an issue for them," she said.

Dr Hannah-Jones said the discussion about same-sex marriage had been hurtful and she had been called "evil" and "unchristian".

"It feels as though they're arguing in some way that God made a mistake when someone like me was created … and that can be incredibly painful," she said.

"They're honestly seeking to do what God's will is, which is what people like me are also doing."

Meanwhile, conservative worshippers claim they are being disciplined and isolated for participating in networks like the Assembly of Confessing Congregations.

Members of the Campsie Uniting Church in New South Wales said they were barred from the church and left to worship on the footpath.

Others claim they had been unfairly undermined and micromanaged, with leadership requesting trip itineraries and details of their daily activities.

Reverend Fihaki claimed his efforts to meet with Uniting Church leadership to discuss tension and the issue of same-sex marriage had been denied.

A sign at a Uniting Church in Adelaide ahead of the 2017 same-sex marriage vote. ( Facebook )

What is the future of the church?

Professor Bouma said the Uniting Church had tried to move forward and adapt to contemporary society and it was not unusual for religious groups to face division on issues like gender, abortion, marriage and euthanasia.

"[The issues are] a kind of litmus test used by some to say, 'Are you actually following scripture or are you not?'" he said.

Monash University Professor Gary Bouma. ( ABC Radio )

The Uniting Church introduced the new rite allowing same-sex marriage alongside the traditional statement, giving individual ministers the choice to perform either marriage.

Church councils also have the right to refuse to hold same-sex marriages on church property.

However, Professor Bouma said imposing a single view on an entire denomination could jeopardise religious freedom.

"The Uniting Church never sought to become uniform and that was part of its delight — it held difference in tension and respectfully," he said.

"The tension is absolute and direct and has to be addressed … the issue fundamentally comes down to is it a difference that can be held within the church or is it one that has to be shoved down the throats [of those] who disagree?

"Can we have difference of opinion on this, or can we have a group demanding that its view be the one that prevails?"

The Uniting Church in Australia refused multiple requests by the ABC for interviews.

In a statement posted to its website, Uniting Church in Australia president Deidre Palmer said the comments provided to the ABC were "in no way authorised by the Uniting Church" and its leaders would "continue to work in good faith" across its "theological diversity".

"The Uniting Church in Australia Assembly's decision to recognise two statements of belief on marriage remains in place," Dr Palmer said.

"This decision allows ministers and celebrants authorised by the Uniting Church the freedom to conduct or to refuse to conduct same-gender marriages.

"I want to reassure all members of the Uniting Church — your rights to follow your beliefs on marriage will continue to be respected and protected."