For Neill Ballantyne, who is gay and a Christian, the likelihood same-sex couples will be able to marry is something to be celebrated.
New Zealand introduced civil union ceremonies in 2005 and since then 2152 couples - 1685 same-sex couples and 467 opposite-sex couples - have opted for civil unions. To all intents and purposes, civil unions are almost identical to marriage. But they are not marriage.
"The institution of marriage holds a lot of cultural value and acceptance and it is important for same-sex couples to have that right.
A separate civil union ceremony, even if such a ceremony is available to opposite-sex couples, is degrading.
It's not about the numbers, it is about rights and choices."
If the legislation is passed, it is not clear whether ministers and priests will be able to opt out of marrying gay couples.
While Ms Wall says they will, a legal opinion obtained by Family First NZ from barrister Ian Bassett says marriage celebrants, including church ministers, will be in breach of the New Zealand Bill of Rights Act and the Human Rights Act 1993 if they refuse to perform their public function because a couple seeking to be married is gay.
It is also not clear how many same-sex couples will want a church wedding. Already, it is estimated only about 20% of marriages are conducted by priests or ministers and have any religious content.
Mr Ballantyne knows some conservative churches and Christians strongly oppose the legislation, believing homosexuality is a sin and allowing same-sex couples to marry strikes at the heart of their theological belief that marriage is the preserve of one man and one woman.
New Zealand's mainstream churches have been grappling with those issues for years.
Some, like the Catholic Church, have definite views and seem in no hurry to review them.
Other denominations have started or completed the debate.
In 1990, Dr David Bromell, of Dunedin, was ordained as the first openly gay Methodist minister in the country, sparking a furore which eventually split the church.
Many members, some ministers and several entire congregations left in protest and established the breakaway Wesleyan Methodist Church in 2000.
The Presbyterian Church, which had allowed the ordination of gay ministers, banned similar appointments in 2004 and went further.
It issued a moratorium saying no-one "in a sexual relationship outside of faithful marriage between a man and a woman" could be ordained or a church leader, effectively ruling out gay people and those in de facto relationships.
The Anglican Church also has a moratorium against the ordination of people living in openly gay relationships. Now it is tackling the issue head-on, establishing a commission to summarise the biblical and theological work done by the church on the ordination of gay priests and same-sex civil unions during the past 30 years.
The commission's report on options and implications of change will be discussed at the 2014 Anglican general synod.
The Rev Dr James Harding, assistant priest at All Saints Anglican Church, North Dunedin, and a senior lecturer in Old Testament studies at the University of Otago, said the debate going on in Parliament was unlikely to influence the views of anyone in the church.
While most church leaders agreed that the Bible was the authority on marriage, they disagreed on how to interpret scripture, he said.
"On one hand, we have conservatives who are very attached to the idea of marriage being one man, one woman, and very attached to the thought that that is the only way to read the Bible.
Liberals, on the other hand, would prefer to look at the quality of relationship that two people have, regardless of the gender they happen to be."
The concept of marriage in scripture developed over 2000 years into "a rich and complicated idea", he said.
"The gay marriage debate raises the point that it is very difficult from scripture to decide, 2000 years after the texts were written and 10,000 miles from where they were written, exactly how to apply them now."
In Old Testament times, 3000-5000 years ago, there was a deeply patriarchal society.
A daughter was part of her father's household and another man paid a bride price for the right to take that daughter as his woman. Polygyny - where a man could marry several women but a woman could not marry more than one man, was the norm.
These days, Old Testament texts were often ignored or mocked, he said.
"You can find that mocking quite easily on the Internet, where Biblical marriage is defined as having 300 wives and 700 concubines or being raped and being forced to marry your rapist."
By New Testament times, the definition of marriage in scripture had evolved.
"That is obvious. It had evolved to the point where the writer of Ephesians, thought to be Paul, doesn't think of marriage in polygynous terms but thinks of it as one man and one woman ...
That picks up on the Creation story, where the woman is created as a companion for the man."
Modern-day churches did not pick and choose randomly what they believed from the Bible, but relied on the New Testament, Dr Harding said.
However, even conservatives inside and outside the church sometimes changed their minds about homosexual relationships.
"Usually, it is because someone they care for deeply is in a same-sex relationship - a child, a brother or sister, or, very occasionally, a spouse who comes out to them.
"They change their minds because they love that person for who they are and they realise their sexuality is not the thing that can prevent them continuing to love them."
Both Dr Harding and Mr Ballantyne believe New Zealand will continue to slowly liberalise its view towards same-sex relationships and marriage.
But Dr Harding said it was much harder to see what direction the churches would choose - whether they would entrench or not.
He emigrated to Dunedin from the UK nine years ago and said Anglican church leaders there who had supported the decriminalisation of homosexuality in England in 1967 seemed to be gradually becoming more conservative in their views.
Whatever happens with Ms Wall's Bill, both Mr Ballantyne and Dr Harding say there will continue to be Christian gay, lesbian and transgender people who struggle to find a church home.
Some, like Mr Ballantyne, will switch from a more conservative denomination or congregation to one they feel is more accepting.
"Unfortunately, I do think a lot of gay Christians lose their faith or move away from the church full stop because they see it as a persecutor, rather than the home it is meant to be," Mr Ballantyne said.
"But I do not think homosexuality and Christianity are mutually exclusive. I hear many, many stories of people who have been able to comfortably bridge the two."
Dr Harding said it was time all churches became more welcoming and "stop being hung up on sexuality".
"I hope the church will eventually start focusing on things that are really important - child poverty for example - with equal energy."
What do churches believe?
The Otago Daily Times asked 12 churches for their view on amending New Zealand's laws to allow same-sex couples to formally marry. Here are their responses. Some have been edited.
Presbyterian Church of Aotearoa New Zealand
Our church has not developed a view on this specific matter. The only body in our church which has the power to approve legislation is the General Assembly, which meets every two years.
Methodist Church of New Zealand
We have not had an opportunity to discuss same-sex marriage and do not have an official policy.
Catholic Church of New Zealand
We have major reservations, mostly because it is attempting to redefine what most people in most cultures actually understand marriage to be, namely the union of a man and a woman for their own mutual support and for the procreation and raising of children. Many Catholic leaders would accept that civil unions affirm the aspirations of same-sex couples to have their lifelong commitment to each other publicly recognised, but such a same-sex partnership is not a marriage.
Anglican Church of Aotearoa, New Zealand and Polynesia
A commission of eminent people . . . has begun the task of clarifying the choices the church faces over the ordination and blessing of folk who are in faithful, committed same-gender relationships and identifying the implications of those choices. It will present a final report to the 2014 General Synod. At its meeting in Fiji last month, the 2012 General Synod also resolved to ask [congregations] to hold conversations with the church and the wider community about the nature of marriage ...Until those discussions have been held and that debate concluded, there is no Anglican Church view, just the views of individual Anglicans.
Jehovah's Witnesses
Jehovah's Witnesses base their firm beliefs on the Bible [and] the view we hold is clear. The Bible disapproves of homosexual acts, but does not encourage hatred of homosexuals. To the contrary, the Bible assures us that God's will is "that all sorts of men should be saved and come to an accurate knowledge of truth". (1 Timothy 2:4) For this reason we ... encourage attendance at our meetings whatever the sexual orientation persons may believe they have. We cannot amend God's law in either the Old Testament or the New Testament, so cannot agree with any laws that would condone same-sex marriage. If the laws are changed by legislation we would still be guided by the laws of God's word, the Bible.
Church of Jesus Christ of Latter-day Saints (Mormons)
Marriage is neither a matter of politics, nor is it a matter of social policy. Marriage is defined by the Lord Himself. The church has a single, undeviating standard of sexual morality: intimate relations are proper only between a husband and a wife united in the bonds of matrimony. The Church's opposition to same-sex marriage neither constitutes nor condones any kind of hostility towards homosexual men and women. Protecting marriage between a man and a woman does not affect church members' Christian obligations of love, kindness and humanity toward all people.
Religious Society of Friends (Quakers)
We believe the same values, benefits, obligations and responsibilities of marriage should be available to same-sex couples as are available to opposite-sex couples. (Minute 11 of our yearly meeting, 2000). Quaker weddings and civil unions, whether same-sex or heterosexual, are conducted during a worship meeting. We have legal exemption from the requirement to have a celebrant. This derives from our historic marriage practice from 17th century England onwards.
The Salvation Army declined to comment. No responses were received from the Baptist Union, Seventh Day Adventists, City Impact Church or Destiny Church.
Gay marriage quotes
What the Bible says about marriage
"[Jesus replied] In the beginning God made a man and a woman. That's why a man leaves his father and mother and gets married. He becomes like one person with his wife. Then they are no longer two people, but one." Mark 10:6-8
"Having your own husband or wife should keep you from doing something immoral." Corinthians 7:2
What the Bible says about homosexuality
"It is disgusting for men to have sex with each other, and those who do will be put to death, just as they deserve." Leviticus 20:13
"Women no longer wanted to have sex in a natural way and they did things with each other that were not natural. Men behaved in the same way. They stopped wanting to have sex with women and had strong desires for sex with other men. They did shameful things with each other, and what has happened to them is punishment for their foolish deeds." Romans 1:26b,27
"Don't you know that evil people won't have a share in the blessings of God's kingdom?
Don't fool yourselves. No-one who is immoral or worships idols or is unfaithful in marriage or is a pervert or behaves like a homosexual will share in God's kingdom. Neither will any thief or greedy person or drunkard or anyone who curses and cheats others." Corinthians 6:9,10
