Psst! Want an old church, anyone? How about one which stands on one of Scotland's most sacred early sites? Govan Old Parish Church may, or may not, be on the market soon. Could it end up as Constantine Carpets on the Clyde, or Karaoke with the Kings? Please God, no.

The Church of Scotland's arbitration panel has decided that the soon-to-be-united charge of Govan and Linthouse, made up of three local congregations, will have New Govan Church as its principal place of worship. What happens to the Govan Old building will be decided by the kirk session of the new united charge.

But isn't this - literally - a parochial story? Yes and no. It raises important issues about how a national church disposes of historic buildings it can no longer afford to maintain, and how a nation preserves its treasures.

Lurking in the background is the question of modern Scotland's troubled relationship with its spiritual heritage. But, first, there are ancient and more modern stories to tell.

Govan was strutting its stuff before Glasgow was even heard of. It was a sacred site for the kingdom of Strathclyde. When Dumbarton was the capital, Govan was Strathclyde's Scone. The upstart village of Glasgow was only built because the invaders from Northumbria wanted an alternative, untainted holy place. (Are you looking at my sacred site, pal?) The site on which Govan Old Parish Church stands is thought to have housed a sixth-century monastery built by St Constantine. There is talk of Druidic worship before that. ("You can feel the vibes, man," a hippy once said to me on the jetty of Iona; well, there was something special about holy Govan, too.) The first parish church was built in 1136 and there has been a church building on the site ever since.

Until the eighteenth century, its ministers held the office of Principal of Glasgow University. Govan Old kirk, which houses a superb collection of early sculpted stones, was built in 1888 under the direction of its minister, the great Dr John MacLeod. A huge man who was described as being "like a sea king, with the drooping moustaches of a Scandinavian chieftain", MacLeod - nicknamed "The Pope of Govan" - opted for a cathedral-type building, with a long nave and a side chapel.

When MacLeod's uncle's great-grandson went to be minister of Govan Old in 1930, the inexorable decline of the shipyards was under way, and the Depression of the 1930s meant that proud Govan became known as a place of poverty and unemployment. Like Pope John before him, George MacLeod is still a legend in the area. A brilliant preacher, broadcaster and stump orator, he was also a superb pastor, and stories of his kindness are legion.

While in Govan, he saw at first hand the failure of the national church to train ministers for tough situations, and it was from the pulpit of Govan Old in 1938 that this fast-rising ecclesiastical star announced that he was abandoning the security of the parish ministry to form the Iona Community. History? Govan Old oozes significant Scottish history.

Decisions about buildings are now having to be made against a background of numerical decline in mainstream churches. The Kirk's membership has dropped from 1.3 million in the early 1950s to around half a million; the Roman Catholic Church faces similar problems about falling numbers and church closures.

The wider cultural milieu ranges from indifference to growing hostility, with increasing numbers openly rejoicing at the decline in mainstream religious institutions. There is a good case for saying the once-dominant churches have had it coming; yet I believe that Scotland is discarding its spiritual roots far too cheaply.

At a time when the hollowness of modern consumerism and the health-destroying treadmill of global capitalism are under serious question, a critical dialogue with the mothers and fathers of the faith was never more needed.

What should happen to old, much-loved buildings at a time when uniting congregations can no longer afford to maintain them? Here in Orkney, two redundant churches were taken over by trusts made up of community and religious interests. The buildings have been preserved as spaces for music, festival events and occasional services. Surely an alliance of interests, initiated by the new kirk session, can preserve Govan Old and ensure that its historic artefacts remain where they truly belong. A combination of imagination and political will could produce a fine auditorium, a setting for lively religious and political dialogue, an area for historical study and a sacred place for the continuance of Govan Old's fine tradition of daily worship.

The Christian family silver must not be sold off to the highest bidder in today's rapacious market. The fate of Govan Old will tell us a great deal about the soul of Scotland itself.