As if banning same-sex marriage isn't enough, the Presbyterian Church has gone a step further and removed the clergy's liberty of conscience on the issue

As point scoring goes, this really taks the cake. Literally, a new vote by the Presbyterian Church of Aotearoa New Zealand takes the wedding cake away from any gay person who wants to get married in a Presbyterian Church, because conducting such a service is now banned. But that's only the start.

The debate about whether gay people could be ministers or elders in the Presbyterian Church, of whici I'm an elder, has been going on my entire adult life. There have been years of often conciliatory discussion. But 10 years ago, in 2004, the church's governing body, the General Assembly, passed a vote with 63 percent in favour that the church would not accept for training, licence, ordination or induction anyone involved in a sexual relationship outside the faithful marriage between a man and a woman.

Not only did that reject gay people from being a minister or an elder, it at the time rejected me, given I was living with my soon-to-be-but-not-yet wife.

At each assembly since, I'm told (although I haven't checked each one), the rule has been challenged but reaffirmed. The PCANZ has been in a conservative phase.

But the gay marriage law opened a chink in the funadamentalists' armour protecting them from the horrors of same-sex relationships. Now same-sex marriage was legal, there was an argument that Presbyterian ministers could conduct such marriages anyway, because the church allows ministers a liberty of conscience. That is, on matters that aren't absolutely fundamental to the church's theology (eg Jesus Christ was both human and divine), there was an 'agree to disagree' clause. Ministers had the freedom to follow their conscience, or at least where they felt God was calling them. The idea of God's call is an important one in Presbyterianism, or at least it was.

No two Presbyterian churches are the same, and they have always been home to a range of theologies, which was a rich part of my life growing up. I worshipped alongside people I utterly disagreed with on all sorts of social and political issues, and was the better for it. I could see people who I felt had quite bigotted views on certain issues take in the the poor and needy and give them a place to sleep, for example. It was a great lesson in delaying judgment and the unifying power of faith.

But this week the fundamentalist arm of the church has voted through several new rules. Not only has it passed a motion to ban same sex marriage in the Presbyterian church, it went further and removed the right for its ministers to have liberty of conscience on this issue. So ministers wishing to find a way to marry same sex couples will be disciplined if they do.

As appalling as I find the ban on same sex marriage, I know many who hold a genuine belief that God calls them to 'hate the sin, but love the sinner'. I utterly disagree that homosexuality is a sin, but I accept their right to a different belief, if that's what they see as right before God.

Yet now those with a view different from mine are officially denying me my right to dissent. Not only are they saying that they want the church to hold to their view of the faith, they are telling others that they are right and we are wrong, that they know God's will and we don't.

The arrogance and presumption is staggering (imagine if the boot was on the other foot) and the vote a major blow to the Presbyterian tradition of thought and education. They are denying me the respect I have shown them over the years and declaring that their faith is better than mine.

How dare they.

The response from many Presbyterians is that they won't walk away and let the barbarians take over their church. Some minsters and churches will just defy the rule, others will protest in other ways. But the consolation that I take from this is that it's a last hurrah for fundamentalism that cannot last.

This vote represents a final, desperate act of a drying creed. The people behind this vote are akin to those who prosecuted Galileo in the 1600s. Society and most Presbyterians – indeed most Christians – under a certain age have no appetite for this anti-gay world view. This too shall pass. As damaging as the vote is today, it is surely a temporary stain on Presbyterianism; history will overcome it and wash it away in years to come.