Parliament allowed civil unions between same-sex couples in 2005. Dr Thompson and her partner Nan Russell had a civil union in her Hamilton church in 2007 and Dr Thompson now leads the church's Waikato-Bay of Plenty region.
What she wants is full equality - if Labour MP Louisa Wall's Marriage (Definition of Marriage) Amendment Bill passes, she and Ms Russell will be among the first to marry.
"Our relationship is no less than any other, so we should have the gold standard," Ms Russell says.
But this is still a minority view among churches. Most church leaders believe redefining marriage to include gay relationships would undermine a basic element in any civilised society - committed faithful marriage between a man and a woman.
"This is Western individualism and post-modernism gone mad - 'It feels good to me, I want society to validate it,"' says Stuart Lange, Presbyterian minister at Massey in West Auckland and co-leader of that church's Bible-believing movement, Affirm.
Submitters from both sides of the churches will take their cases to the select committee on Ms Wall's bill when it resumes hearings next week in Auckland.
Their arguments matter because many New Zealanders still want a Christian marriage. If the bill passes, each church will need to decide whether to let its ministers marry gay couples.
The orthodox view
Paul's words in 1 Corinthians 6 are explicit: "Neither the sexually immoral nor idolaters nor adulterers nor male prostitutes nor homosexual offenders nor thieves nor the greedy nor drunkards nor slanderers nor swindlers will inherit the kingdom of God."
Dr Lange cites a Presbyterian Church resolution in 1985 supporting decriminalisation of homosexual acts and upholding God's love and grace towards everyone, but also reaffirming that homosexual behaviour was "sinful".
"In 1991 it declared that God's intentions for human sexual relationships, as affirmed by Jesus, are loving, faithful, mutual relationships between men and women," he says. "Sexual relations outside marriage fall short of God's intentions."
This is still good social policy, he argues. If possible, children need a mum and a dad so that they can "download the software" of how a girl can grow into a woman, how a boy can become a man, and how to relate to the opposite sex.
"The essence of marriage is the complementarity of the two different sexes." Men and women are different, but they "complete" each other.
Glyn Carpenter of the NZ Christian Network says MPs should not change the meaning of the word "marriage" lightly.
"This is the same as saying we are now going to start calling elephants 'horses'," he says.
He fears that human rights law, and an existing section of the Marriage Act making it illegal to allege that someone who is lawfully married is not "truly and sufficiently married", might be used to prosecute people who refuse to use the new definition.
He asks for a royal commission to consider the evidence on both - whether the change would improve the wellbeing of gay people and its potential broader social effects.
Christian historian Dr Laurie Guy argues in a submission that, rather than redefining marriage, any lack of rights for gay couples could be addressed by amending the civil union law.
"The fact that there is an alternative solution to the question of rights may suggest that the amendment is not really about rights but about recognition and affirmation," he says. "It might popularly be captioned a 'gay is good' bill."
The liberal view
And that is exactly how many passionate submissions from the gay community see it. Steven Oates, 37, who hosts a gay show on Radio Ponsonby, recalls the abuse he endured growing up in Taupo.
"I was labelled the class faggot and as a result was frequently teased, spat on, excluded from activities, had anonymous phone calls to my family home informing whoever answered that I was gay, and was once so badly beaten after a school blue light disco I had my cheek bones fractured.
"Marriage equality will not stop hate crimes or prejudice. But it will send a message. It will tell all those who reside in our country that the government values all citizens, even the gay and lesbian ones."
Mark Henrickson, 57, an Anglican minister and social work professor at Massey University, was walking his dog alone near his Auckland home late last year when a middle-aged man screamed "Faggot!"
"It's happened three times in the last six months," he says.
Paul Franken, 77, went to a funeral in Masterton before Christmas where the dead man's gay partner of 12 years was not acknowledged by any of the family.
"One of the sons came over to me afterwards and said we are sorry about it, we didn't know how to handle that," he says.
It is actually common ground on both sides that not every Bible verse can be interpreted literally. Dr Lange says passages requiring wives to submit to their husbands as "head" of the household, and banning women from preaching or exercising authority over men, were written to deal with specific problems in local churches 2000 years ago and should be read in the context of Jesus's "revolutionary" view that men and women were equal in the sight of God. "Most Christians now freely believe that women have a role in leadership within the church because we take the Scripture as a whole," he says.
Similarly, Dr Thompson believes that passages condemning homosexuals are overridden by God's "inclusive love".
"I look for the big themes of the Scripture, the big themes of love and justice," she says.
"I look for the way Jesus lived in the Gospels and the relationships he had with people, the way he welcomed everybody, the way he sat at the table with people who were regarded as sinners." She says marriage has evolved from a relationship mainly about property to one based on love and commitment from which there is no longer any reason to exclude same-sex couples.
Even for bringing up children, the expert consensus is, to quote the American Psychological Association, that "there is no scientific evidence that parenting effectiveness is related to parental sexual orientation".
The Advisory Committee on Assisted Reproductive Technology says in a submission that it has researched the literature on gay male parenting and "did not find evidence of harm that justifies excluding single men and male couples from seeking ethical approval to enter a surrogacy arrangement".
"What counts for children are family functioning, not family structure, and the nature of the relationship between parents and child, not sexual orientation."
Ongoing debate
The bill has sparked an emotional outpouring - 20,000 submissions, including about 18,000 form letters. Out of 1790 substantial submissions posted online by this week, 769 support the bill and 1017 oppose it (a handful are ambiguous).
Only 14 out of 66 submissions from clerics and religious organisations supporting the bill, while the 52 against include the national leaders of the Catholics, Presbyterians, Seventh Day Adventists, Salvation Army, Wesleyans and several Pacific churches.
In Ms Wall's Manurewa electorate, Pastor Stephen Miller says a letter opposing the bill from the Manukau Ministers Network was signed by all 25 ministers. No one refused.
Even among those who stayed in the Methodist Church after the 1990s split, there is no pro-gay consensus. Dr Thompson says the bill was not raised at the last Methodist conference in November because "there is still so much diversity of opinion that we wouldn't have come out for or against".
The Presbyterians did vote on it at their assembly in October, where 77 per cent voted against the bill and almost 60 per cent voted to ban ministers from conducting same-sex marriages. But this second vote fell short of the threshold to become church law, so ministers will be free to marry gay couples if the bill passes.
The Anglican Church has set up a commission, headed by former Governor-General Sir Anand Satyanand, to develop options on the ordination and blessing of people in same-sex relationships.
Votes in Auckland, Waiapu (Napier) and Dunedin synods have supported ordaining gay ministers, but Waikato, Wellington, Nelson and Christchurch are opposed.
Bob Scott, a veteran gay minister ordained in the days when "people knew but you didn't discuss it", says repeated attempts to win support for ordaining gays in Auckland were "inconclusive and usually lost" until a dramatic shift in 2011.
"Suddenly in that year when the vote was taken it was a huge change - in the clergy 115 in favour and 18 against, in the laity 140 in favour and 30 against," he says.
"The difference was that we encouraged people who had never spoken on it before but had friends or members of their families who were gay, so it got on to a new level."
St Matthew-in-the-City vicar Glynn Cardy says society is changing and the church is "not immune". This week a leading British evangelical Baptist, Steve Chalke, switched sides and endorsed monogamous same-sex relationships.
"There will be a similar thing in New Zealand over the next decade," Mr Cardy predicts. "I just see it as an inevitable part of change."
