Jonathan Brown: Old enmities at risk of being resurrected in city divided by faith

The Pope has chosen a tough venue for first leg of his tour

Monsignor Christopher McElroy was shaking hands with the dozen or so worshippers with whom he had celebrated Mass in Glasgow city centre yesterday morning. St Andrew's cathedral is the centre of Catholic life in Scotland. Built to cope with the soaring numbers arriving from Ireland and elsewhere looking for work in the thriving industry here at the beginning of the 19th century, it is currently being repaired and extended in anticipation of congregations new. Morning Mass meanwhile adjourned to an annex.

A priest of 30 years standing, the Monsignor has witnessed Catholic church attendances overtake those of the Kirk in an increasingly secular Scotland – the change fuelled in part by the arrival of Eastern Europeans and Africans over the last decade and the rejection of organised religion by many Scots. He said that the visit of Pope Benedict was an opportunity for Scotland's 850,000 Catholics to celebrate in a city struggling to shake off its notorious sectarian divide.

"Glasgow has changed. There is more tolerance and acceptance but there is still bad feeling that raises its profile at difficult times. Most people get on well together and people in the churches get on very well. The problems tend to be on the fringes among the people who use religion as a banner to give themselves an identity," he said.

But it is impossible to escape Glasgow's particular brand of identity politics and the problems it throws up. It has more marches by Protestant loyal orders and Irish Republican parades than Northern Ireland's two biggest cities combined. The most recent figures show that in one 18-month period following the introduction of new anti-bigotry laws in 2003 in Scotland there were 532 reported cases of religiously aggravated offences, with Catholics five times more likely to be victims than their Protestant neighbours.

The sectarian faultline that runs through the city is most spectacularly and violently manifested in the fanatical support afforded the two football clubs, Celtic and Rangers. So fraught is the symbolism that Rangers reportedly took eggs benedict off the menu when Cardinal Ratzinger became Pope in 2005, though in a sign that things have mellowed since then the club has agreed that elderly pilgrims can use its car park ahead of the Mass at Bellahouston Park.

Over at the Louden tavern on Duke Street, on those run-down fringes where the remnants of the two communities still live cheek-by-jowl in the shadow of Celtic Park and where the Red Hand of Ulster flutters just a few blocks from the Irish tricolour – the lunchtime crowd was relaxing over a few pints and a game of cards. The Louden is blue to its core. Photographs and drawings of Rangers' heroes down the ages decorate every available inch of wall space.

"We don't welcome the Pope here," said John McGowan, 47, unemployed, as he laid another Union Jack card down on the table.

"Why should motorways be shut down and we have to pay £20m for someone who supports incest and child abuse?" wondered Billy Simpson, 41, also unemployed. "In Africa they are told they are not allowed to use condoms so children are being born with Aids in some of the worst places in the world," he adds.

The men talk reverentially about the highly charged atmosphere of the Old Firm matches when Celtic and Rangers clash, and bitterly object to attempts to stop them singing what they consider to be "traditional folk songs". Mr McGowan says his son was fined £400 for singing "The Sash" at a match. He also said he recently forbade his daughter from seeing a Catholic. "I got rid of him straight away," he says as the other men laugh.

Just outside Glasgow in the new town of East Kilbride, Pastor Jack Bell is explaining his plans to take up to 20 of his parishioners from the Zion Baptist church to Edinburgh to demonstrate alongside Ian Paisley and others against the Pope's visit. Mr Bell, quietly spoken and polite, objects to the timing of Benedict's arrival as Protestants celebrate the 400th anniversary of the Reformation. He says he has no antipathy towards Catholics – only their church. "I stand by John Knox's statement that the Pope is the antichrist and the Church of Rome is the Synagogue of Satan," he says.

Bairds Bar on Gallowgate in Glasgow's Barrowlands is a shrine to all things Celtic, and yesterday owner Thomas Carberry, 59, said he had been fielding telephone calls from people saying "fuck the Pope". "These are not kids, these are grown men," he says. But according to Mr Carberry there is none of the excitement of the previous Pope's visit. "There doesn't seem to be much enthusiasm about it. We were going to do the pub up but no one came forward."

One local, who was a steward in 1982, said he had had enough of the Catholic church. Educated at a local school, he recalls the headmaster breaking a boy's nose in front of the whole school by smashing him in the face with a set of keys for getting involved in a playground fight. "That was it with religion for me," he says.