LINDISFARNE lies beneath a fresh white blanket, wind wilful, causeway causing concern. "It's a bitter morning," says the warmly welcoming Brother Damian, "even for here."

In the summer there may be 10,000 visitors a day, in the winter there are just 140 semi-detached inhabitants - six of them priests. Ours is the only vehicle in the oft-overflowing car park, the castle rising across the pristine fields beyond.

The temptation to ignore Berwick-upon-Tweed district council's demand for £3 in the meter is resolutely resisted. This is Holy Island. Not only hasn't there been a crime in living memory, but there may be a commandment against it.

Sunday's principal service at the Anglican church of St Mary's, numerically England's smallest parish, starts at 10.45am. Even at 10.30, even on Holy Island, there are those who wander in, realise that the church may actually be about to celebrate an act of worship and not do a half-price offer on Lindisfarne Mead, and self-consciously wander out again.

There's a heater beneath the pew, a luxury doubtless denied to those who followed the Irish monk Aidan to Lindisfarne in 635AD, when the first Celtic monastery was established. Cuthbert became prior in 674, bishop 11 years later.

Brother Damian, the present vicar, is a member of the monastic Society of St Francis. If the organist leaves suddenly, he announces, it's because he has to be back on the mainland before the noon tide again separates the island from the remainder of Northumberland.

The opening hymn is Praise to the Holiest in the Height. It's half way through the second verse before still-numbed fingers have found the page.

The church, the island's oldest building, dates in part from the 11th century and attracts 140,000 visitors annually. The ruined Benedictine priory behind it was dissolved, though the word seems barely adequate, by bad king Henry in 1537.

Prayer has probably been offered on this site for almost 1400 years, and is much encouraged now. It is a living church, they insist, not a museum.

The sermon is preached by Canon Kate Tristram, historian and expert on Celtic Christianity and the Lindisfarne Gospels, whose 75th birthday it is. As a present we sing her favourite hymn, All My Hope on God Is Founded.

Canon Kate, as affectionately they call her, bears a remarkable resemblance in both speech and mannerism to Bishop David Jenkins, formerly of Durham, and was taught by him when studying for a second Oxford degree.

None, she gently insists, has suggested the likeness before.

Unable to be ordained because she was a woman, she taught at St Hild and St Bede college in Durham, came to Holy Island in 1978 to work at Marygate House - a retreat and pilgrimage centre - and became its warden.

"I had a remarkable experience which told me I was coming to work here, but it's amazing I survived," she says after the service. "I'm not domesticated, never have been, but these have been the best years of my life."

Now she is associate priest at St Mary's, completed a masters degree in her seventies, abandoned a later PhD at Durham when it wasn't working out and has almost finished a book on Columbanus, an Irish saint.

An earlier novel, about a monk called Egfroth, failed to find a publisher. It still disappoints her.

The Lenten sermon is on death and suffering - powerful, punchy, precise. Someone once said, recalls Canon Kate in a moment of light relief, that a man undergoes a kind of death on the day he realises that his son can run faster than he can.

There are prayers for the "people of Slobodan Milosevic-land" and for The Hague tribunal - "as they prepare to face the truth" - and for John Profumo "who redeemed his later years".

The wind rattles the door frame but is refused admission. Though none casts a clout, it's warming up nicely. About 50 are present.

The atmosphere is inescapably special, the service ends at 11.48am, followed by a 20-second organ voluntary. The organist almost simultaneously pulls on his snow shoes and heads, causeway and effect, for the mainland.

Brother Damian offers coffee and a new tin of shortbread in the vicarage, now also a monastic pilgrimage house, across the road.

We are joined by the brown cassocked Brother Robert, pipe clamped between his teeth in the manner of Kenneth More playing Douglas Bader - Robert was RAF, too - and by Canon Kate.

It's warm and comfortably furnished. Somewhere are the radio controlled cars which one of the lay readers bought the two brothers for Christmas. "We spent half Christmas Day racing," confesses Brother Robert.

Canon Kate says that one of the things she misses is being near a really good bookshop - "Your house is a bookshop," says Brother Damian - while Brother Robert, a layman, is asked if he prefers winter or summer on the island.

"Winter is peaceful, summer is exciting," he replies diplomatically. A lay brother, he is also church council treasurer, parish council clerk and "unofficial" chaplain to the island's two pubs.

Brother Damian was born in London, left school as soon as he could, took a job in an accountancy office and was sacked after three months.

Seeking another job in the financial department of the United Society for the Propagation of the Gospel, he was asked if he thought he had a vocation for it. "Then will you do it for half your present salary," they said when he answered in the affirmative.

A Francisan friar for 40 years, he became Provincial Minister - a worldwide role - and came to Holy Island in 2003, the first monk to be parish priest.

"They put me on an island off the Northumberland coast and told me to get on with it," he says, cheerfully. "There was a bit of suspicion from the locals, but my first concern as vicar is still the pastoral care of the people of the island," he says.

His work is also a ministry of welcome. "We walk," he says, "in the footsteps of St Cuthbert."

Outside, the snow's falling with renewed vigour, the mercury around zero, the stony old streets almost deserted. It'll be another three and a half hours before the causeway can safely be traversed, the pilgrims' progress resumed.

There's no rush, no hurry. None can invade now. On a wintry March day, Holy Island is treasure island, too.