Sex and the schism

This year's Moderator for the week, the Right Reverend Bill Hewitt, will preside from the Moderator's Chair, surrounded by the clerks and officials of the Assembly. As usual they will all sit inside a fenced enclosure known universally as "the playpen", surrounded by 700 "commissioners".

Only this year the playpen could turn into a bearpit. The Moderator is the General Assembly's equivalent of the House of Commons Speaker, and Hewitt will need to keep a tighter rein on proceedings than his Westminster counterpart if trouble is to be avoided.

The opening shots in a very unholy war of words have already been fired. The cause of the conflict is whether or not openly gay minister Scott Rennie will be allowed to take up his post at the Queen's Cross Church in Aberdeen after its congregation voted overwhelmingly to offer him the post. Rennie, a divorcee with a daughter who lived openly in a same-sex relationship while minister at Brechin Cathedral, has made it clear that his partner David will move into the Manse.

The issue is the latest round of a battle between liberals and traditionalists in the church, but the stakes have been raised dramatically by a motion to the Assembly from the Presbytery of Skye-Lochcarron which is to be debated on Saturday. It is short and pointed: that "this Church shall not accept for training, ordain, admit, re-admit, induct or introduce to any ministry of the Church anyone involved in a sexual relationship outside of faithful marriage between a man and a woman". This isn't just about gay ministers. It's about the Kirk, marriage and sexual morality.

The pressure has been ratcheted up in a move by the evangelical grouping The Fellowship of Confessing Churches, whose petition objecting to Rennie's appointment has already garnered 11,000 signatures. Almost 400 Church of Scotland ministers, an incredible 40 per cent of its total, have signed . There is dark talk of schism.

"Life in the Church will never be the same again (if Rennie's appointment stands]," said the Reverend Kenneth MacKenzie, the minister at Crathie Kirk, near Balmoral, which is attended by the Queen. "My fear is that a sizeable minority of its clergy, and perhaps a majority of its people, may consider leaving the Church, causing a rift felt in every parish."

The Church is more polarised than at any time since 1843 when 450 ministers left to set up the Free Church over the right of congregations to choose their own minister. Unlike past disputes where a fudge was possible, this time there can be only one winner: Rennie is either allowed to minister or he is not.

"There's no middle ground on this," said Reverend John Mann of Affirmation Scotland, a group campaigning for the rights of gay and lesbian clergy. "Scott Rennie is by no means the only gay minister but he's the first one to step forward and be open about it. I'd compare him to Rosa Parks (the black woman whose refusal to give up her seat on the bus to a white passenger gave birth to the US civil rights movement]. He's the man who wasn't prepared to go to the back of the bus and shut up."

Those who vehemently object to having a practising homosexual as a minister beg to differ. The most strident opposition came last week from the Reverend Ian Watson, the minister at Kirkmuirhill Church in Lanark and head of the influential evangelical movement Forward Together. In an incendiary sermon worthy of John Knox, he invoked Martin Luther, John Calvin and the Apostle Paul as he compared those who would let Rennie preach to those who appeased the Nazis.

"To claim that the homosexual lifestyle is worthy of a child of God; to demand that a same-sex partnership be recognised as on a footing with marriage; to commend such a lifestyle to others is to deny that Jesus Christ is our only Sovereign and Lord," he said. "It is to turn the grace of God into a licence for immorality."

The row has a significance that stretches outside strict ecclesiastical confines. The Church of Scotland isn't just the biggest single church in the country, with 42 per cent of people professing an allegiance and congregations totalling 500,000 Scots each Sunday; its annual shindig is a national institution which in pre-devolution days took the place of a Scottish parliament and laid down moral and social codes for the nation. It was no surprise that when Margaret Thatcher wanted to address the Scottish nation in 1988, she did so at the General Assembly in the now infamous Sermon on The Mound.

Spiritually and morally, the General Assembly has represented the whole nation. Although there have been exceptions – the demonisation of Irish immigrants; the persecution of the Covenanters and the hanging of drunk student Thomas Aikenhead for blasphemously questioning the existence of the Trinity stand out – while doing so it has been notably more pragmatic than the Church of England, generally placing expedience and order before fundamentalist orthodoxy.

The Kirk has been a bulwark of liberalism, proving itself well ahead of the curve on contentious issues such as woman priests (introduced 40 years ago), allowing divorcees to remarry in church, and even same-sex marriage, which was approved by the General Assembly in 2006. The lack of a Monarch as spiritual head and the devolving of power to the grass-roots has created a democratic climate, while the Westminster Concession has allowed different parishes to follow their conscience in different ways.

The Kirk's structure is important because it demonstrates the unprecedented nature of the assault by the evangelical wing. Fundamental is the ability for each parish to "call" whatever Minister they choose, the issue that caused the schism of 1843. If the decision of the Aberdeen presbytery to appoint Rennie is overturned by the adoption of the motion on Saturday, it will be the first time in 150 years that a presbytery has been overruled.

Son of the manse Lord Steel, the former Liberal leader and presiding officer at Holyrood, believes the only way to avoid conflict is for the evangelicals to respect the Kirk'sdecision-making process. "I hope the Church's traditional liberal position is maintained," he said. "He (Rennie] was backed by the congregation (at Queen's Cross] and that has always been the formal process in the Church of Scotland. In other words, live and let live. Former General Assemblies have always upheld that position, and I certainly hope the more fundamentalist bloc don't prevail."

Neither side is showing any signs of backing down, not least because the debate is a cipher for a wider debate about whether the church should seek to lead or follow on moral issues. This row over sexual morality exposes a fundamental split within the Kirk on its role in society.

On the one hand are liberals such as acting principal clerk Rev Dr Marjory MacLean, a lawyer with the mien of a senior civil servant. This faction holds sway at the Kirk's George Street headquarters, and wants an inclusive, non-judgmental church that reaches out to everyone.

This is the wing that believes that even if the relevant scriptural passages in Leviticus were recorded correctly (which is open to debate), the church still has a duty to move with the times. They point out that Jesus's only instructions to his followers were to love God and love your neighbour as you love yourself. Besides, they say, we don't still believe that it's okay to have slaves and sleep with them just because it says so in the Bible; nor do we beat adulterous women or insist women wear hats, or handle serpents to show our faith, or forbid masturbation. So why single out homosexuality?

On the other hand are men such as Rev Professor Andrew McGowan, who set up the Highlands Theological College and ministers to the biggest church in Inverness. This is the more fundamentalist wing of the Church, which has a far more straightforward approach to scripture, seeing it as the word of God. Many come from the north of the country and the islands, and there's a growing feeling of exclusion. The lack of a Moderator from the Kirk's heartlands north of Inverness for the past 15 years particularly rankles.

That sense of disenfranchisement has propelled Ian Watson to the head of an evangelist movement that feels its time has come. He's a lawyer with an acute mind, a hardliner who one acquaintance described as "not a fundamentalist but absolutely adamant on this, and he's attending the Assembly which is why he will emerge as a key figure."

Their position is encapsulated by Dr Calum MacKellar, an elder at North Leith Parish Church, who believes a split is imminent on the issue. "I am praying for unity but I don't see how a solution is going to come about," he said. "Neither side wants to see the Church split over this issue. But it is very black and white situation - and it's not just about homosexuality, it's about the authority of the Bible and the Church. The Bible is the word of God and even though you don't understand why God is opposed to something, you just accept it."

One of the root causes of the argument is the dismay of those in the church at the dwindling attendances in Church. Both sides talk about reinvigorating the Church, but their real preoccupation is quite different, says John Bell of the Iona Community.

"This is all about the need for a scapegoat for people's angst at the failure of the religious life to which they've devoted their lives," he says. "The profile of religion is not as high as it once was and they're happy to blame the fact that there's gay people in the Church. But despite all the prayers, they have no answer to the fact that God keeps creating gay people and calling them to the Church."

For all the emotions unleashed on both sides of the debate, the unedifying sight of warring ecclesiastical factions scrapping over the Kirk must look like two bald men fighting over a toupee to the general public. Many church-goers appear bemused and irritated by a dispute they see as divisive and unnecessary.

Susie Cunningham, a fortysomething elder of Skelmorlie & Wemyss Bay church in Inverclyde, says that "I can categorically say that I've never heard anyone express an opinion on the subject. The Church needs to be all-embracing, particularly when it comes to young people. My children have been brought up with very different attitudes and are far more accepting. Even my peer group are pretty bemused."

Pensioner Prilla Thorburn, who attends Fairlie Church in Ayrshire, was equally non-plussed. "The frustrating thing is that the only time a lot of people know about the Church is when we have rows like this," she says. "But even at a church like mine where 75 per cent of people are over 50, it's just not something people are talking about. Our minister Jim Whyte preached on Sunday about the need to be tolerant and while some people will allow their prejudices to overcome their Christian compassion I think most Christians want to be inclusive."

Thorburn has seen countless spats like this, she says, laughing about the time her father threatened to leave the Church when women elders were admitted. "He didn't, of course, but then they never do and it'll be the same this time: dissenters just grin and bear it and get even more bitter, it's always been that way," she said.

Her optimism may be misplaced, though. Although conservative clergy are highly reluctant to talk in public, in private many admit they are contemplating moving to the Church of England, the Free Church or setting up a new church. Even losing 20, 30 or 40 ministers would be a real body blow to a Church with a huge shortfall in the ministry, but the showdown is imminent.

"This coming week will be fundamental to the future of the Church," says John Mann, "because we see it as a justice issue and they see it as going to the core of their belief-system. In those circumstances, neither side is going to give in."