It's easy to forget.

What's known as sexual "activity" between people of the same sex has only been legal in Scotland since 1981. The right of LGBT individuals to serve openly in the armed forces has existed only since 2000. Civil partnerships, the merest of legal formalities, went unrecognised until 2005.

For most, this is belated progress, but progress nevertheless. The least you can say about the majority is that they are no longer outraged by equality before the law. Poll after poll testifies to the fact. The arrival this year of same-sex marriage across most of the United Kingdom was not widely perceived as the end of civilisation itself. Instead, when it was not celebrated the right was accepted without a second thought.

It wasn't always this way. Equally, it would be naïve to ask why Northern Ireland still bans same-sex marriage without first having an inkling of the reasons. No religious body in these islands is compelled to perform such marriages; the Church of England and the Church of Wales forbid their priests from conducting services.

At the risk of a banal analogy, imagine if race was the question of identity at stake in these matters of clerical conscience.

Some among the religious find the comparison insulting. They are guided, they insist, by the Bible, not mere prejudice. They find refuge in a formula involving God's love for the sinner and intolerance of the sin. The words "practising" and "open" pepper their statements, as if to say that appearance and concealment are all that matter to the deity. They see no progress, it's fair to say, in decades of reform.

But then the Christian churches themselves are often far from united. Their struggles for compromise and consensus over sexuality can seem risible to a wider world that is relaxed, increasingly so, about rights and choices. The struggles are no less real for that. In fact, they are a better barometer of progress than most. Scripture, it turns out, is more than a little ambiguous in these matters. When or if believers come to that truth, consequences follow.

For now, the Church of Scotland is still coming to terms with the aftermath of the 2009 appointment by a church in Aberdeen of the Reverend Scott Rennie, gay and unashamed.

Some congregations, wealthy ones among them, have quit the Kirk. Some ministers, fundamentalist and evangelical, have sworn mighty oaths. The latter group, by no means united, have pondered how far they are prepared to go for the sake of doctrinal purity. The Kirk's General Assembly, opening today, will reveal their thinking.

Given its structures, the Kirk ought to be an ideal vehicle for compromise. It ought to be able to allow gay ministers, but also to allow congregations a choice in the matter. The deal - if that's the word - is on the table. Whether all evangelical types are prepared to accept even the existence of ministers who have "a same-sex attraction" but who decline to remain celibate is the question. The likely answer: probably not.

These are anxious times for the Kirk, then. For the rest of us, the controversies are in an odd way reassuring. Less than a generation ago the spectacle of this church performing these contortions over the issue would have been unthinkable. Even in this country, LGBT rights are a very long way from secure. But it was not so long that a headline along the lines of "Row over gay ministers" would have been the stuff of a campaigner's fantasy.

This August will mark 60 years since the Wolfenden committee sat down to begin work on a report into "homosexual offences and prostitution". No-one thought the juxtaposition strange. A minister of the Church of Scotland, one RFV Scott, contributed to the discussions, along with the former Glasgow Procurator Fiscal James Adair, and - for why not? - Mrs Mary G. Cohen, vice-president of the City of Glasgow Girl Guides. These and others helped to establish the idea that "homosexual behaviour between consenting adults in private should no longer be a criminal offence".

That notion did not become law in England Wales until 1967. Scotland, perhaps typically, had to wait until the Criminal Justice (Scotland) Act 1980, but even then society drew another of the lines of which it is fond.

Perversely (in the proper sense) the Scottish legislation set the age of homosexual consent at 21, despite the fact that the equivalent heterosexual age had been 16 since the late 19th century. Once again, equality was postponed, in this case until the Sexual Offences (Amendment) Act 2000.

Those who detect in the progress of LGBT rights the onward march of immorality can therefore admit this much: as stampedes go it has been an erratic, slow-motion affair.

Countless individuals spent their lives fighting for an equality they would never enjoy. Plenty of grown Scottish men have gone through their adulthoods as designated sinners, loved by the pious - theoretically - despite their sin, but moving targets because of their identities.

The 1980s were not the best of times for gay men, in Scotland or anywhere else. Here, nevertheless, there was a cruel coincidence in the nit-picking bigotry behind the appearance of the Criminal Justice Act and the arrival of HIV/AIDS.

For a while, the deaths of contemporaries, of friends and friends of friends, became news as commonplace as it was grim. Hearing those young men damned by zealots who claimed knowledge of God's purpose was like catching an echo from the Middle Ages.

That noise has diminished somewhat. You could call the fact another sort of progress. Yet was it only in 2000 that we were fighting rhetorical wars as MSPs prepared to rid the country of "section 28" and its bizarre notion that homosexuality could be "promoted"? Even then, Government ministers felt obliged to compensate the Keep the Clause campaign by inserting material on the importance of marriage into sex education guidance for schools. Predictably, this was before opponents realised that gay people might also consider marriage important.

Such is one odd, distinctive aspect of recurring protests from some of those who quote Scripture. Whenever one issue is settled, another is raised. So the sanctity of marriage had to be upheld if section 28 was to be lost. But if gay people sought marriage, most of the section 28 arguments could be forgotten in defence of the only "true" man-plus-woman marriage.

At every turn, the urge to demand a proper answer of the professedly godly has been strong: Just say what you really mean about LGBT people and what you understand of church doctrine. Instead - this might count as another mark of progress - it has become hard to find outright sexual bigots in public places. They no longer say what they think. Rhetorical queer-bashing no longer passes without comment.

Not so long ago actual assaults on gay people were treated as jokes in Scotland's cities. Incredible libels were uttered by individuals who would have found the sexual politics of Vladimir Putin congenial. The law, such as existed, was useless. Most progress is slow, but the Kirk has another chance to do its wee bit for decency over the coming week.