As each General Assembly of the Church of Scotland comes round, I find myself reflecting on an all-too- accurate parody of a verse from "Onward Christian Soldiers":

"Like a mighty tortoise

Moves the Church of God,

Brothers, we are treading

Where we've always trod."

So it was with the report that the Kirk's Ministries Council has concluded that the traditional model of "one parish, one building, one minister" may become the exception, and that dedicated part-time teams made up both of ordained and lay people may have to look after a number of parishes.

In the course of research for a forthcoming history of the Church of Scotland since 1945, I made the discovery (which came as no surprise) that every report on the future shape of the ministry since the end of the Second World War has reached the same conclusion. If the Church is to be an effective national church, bringing what are quaintly called "the ordinances of religion" to every part of Scotland, the pattern of most ministers working on their own, in single parishes or several linked together, is neither appropriate nor sustainable.

That scenario, of course, makes a number of assumptions. In the 21st century, does it either make sense or reflect reality for the Church to claim that, whatever other denominations may do, it must be present everywhere in the country.

The Church's continued reliance on a full-time professional ministry (increasingly unaffordable and less professionally qualified) effectively undermines the role to which it has consistently said it is committed: the involvement of the whole "people of God" in sharing the Gospel with the communities where they live.

In the late 19th century, where people lived and where they worked increasingly became separated and the Church began to concentrate its presence in congregations centred on where people lived. The Church and what it represented became associated with people's spare time and church membership became, more or less, a leisure activity. Ministers became, in the words of the late Professor Ian Henderson, "chaplains to congregations and no longer ministers of parishes".

This has resulted in one of the great "disconnects" between the official view of the Church and the attitude of its members. Recently the Acting Principal Clerk of the General Assembly was quoted as saying the Church was "naturally disappointed" at the reduction of the Kirk's membership last year by 50,000 members but that "there are many more people who take part in church life but are not on the formal roll".

The Church must seem very different viewed from an ecclesiastical bureaucrat's desk than from a parish minister's pulpit.

In his book Freedom and Faith, Donald Smith sees a link between the Church's structures and the issue of same-sex relationships, which will probably dominate the General Assembly. He writes: "The Church of Scotland turned to secular management systems to quell the Presbyterian love of debate in favour of 'official lines' on contentious issues such as same-sex relationships. The General Assembly was disempowered by managerial complexity, while the work of the Church as a national institution became the domain of a professional administration intent on institutional survival."

There was a time when politicians visited the Assembly and praised the quality of its debate. Not now. What meets today is no longer the sort of challenging, controversial, self-critical, prophetic voice of a vibrant Church but the equivalent of the annual general meeting of the Church of Scotland plc.

Those presenting reports used to relish stimulating the Assembly with provocative reports. Now they often proudly claim that the resolutions they proposed were all accepted.

It all seems like the church equivalent of the old jibe about having created a desert and then called it peace, but it is worse than that. A desert has been created and it will be called "challenge".