ARCHITECTURE: The picture of peace and passion

Jerusalem: the Holy City, three times holy to the 400 million Christians, Muslims and Jews, is to be celebrated in a remarkable painting by artist Ben Johnson. He hopes that his work will enable people all over the world to see Jerusalem as an expression of hope. The Vatican wants to exhibit it. And last week Michael Grade of the New Millennium Experience came to West London to admire the painting but decided that our own walled city, the Faith Zone inside the Dome, may not be the right site in which to reveal this celebration of the architectural heritage of three different faiths.

In 5,000 years, Jerusalem has withstood pillage, plague and pestilence, including the fire of 1898 and the earthquake of 1927, religious and territorial conflict. Now this painting of Jerusalem brings the message of its patron, Iranian-born Dr Nasser David Khalili, that in the new millennium will be possible for different religions to live together in peace and harmony. A bit of a tall order, but David Khalili, who is Jewish and a collector of Islamic and Oriental art, started the Maimonides Foundation to bring Muslims, Jews and Christian Arabs together through culture and common heritage.

"If you keep walking towards each other, peace is possible. There is a meeting point at the end of the day," says Dr Khalili. It occurred to him that, on the path to peace, it was important to have a painting of the Holy City that would show the world "an eternal map of Jerusalem".

Inspired by Ben Johnson's cityscape of Hong Kong which showed a modern city constantly reinventing itself as a temple to corporate power, David Khalili commissioned a painting of the Holy City of Jerusalem, "a very different city," as he observes.

The brief was simple, if exacting. All the buildings within the walled city, some 30,000 of them, were to be depicted to scale. The three most significant religious sites of the ancient world - the Western Wall, the last vestige of the ramparts that surrounded the holy temple of the Jews; the Dome of the Rock, recognised by Jews, Muslims and Christians as a holy site, and the Holy Sepulchre, built on the site of Christ's resurrection - had to be equal in prominence and faithful to the original. Johnson took a week to paint the Western Wall in the centre of the painting, with every stone in exact scale, but he realigned the square upon which the golden Dome is set and turned the edges of the Sepulchre towards the horizon.

Ravenscourt Park in W6 is an unusual London location in which to see the whole of Jerusalem's walled city bathed in a golden light. Or at the flick of a switch, in the white of early dawn, or beneath glowering thunder. Johnson's studio has every special lighting effect with chemically coated fluorescent tubes to change the mood of the painted city.

Not only the light over Jerusalem is manipulated. Every one of the 30,000 or so buildings on his canvas imperceptibly tilts towards the vanishing horizon. This artists' trick frees busy streets without any distortion, while at the same time it seductively draws in the spectator. All the shadows of every building are oriented towards that horizon.

Johnson aligns himself with Deconstruction, the architectural response to the universe in chaos with a geometry that forever uses the diagonal, the moment of impact. His response to that fragmentation is to tilt the city towards its horizon. He reproduces with fine economy of line every building, true to its form, and in the right position which in turn imposes upon the labyrinth of the Holy City a peculiar calm.

Half dazzled, you stare at the eloquence of the bedizened city which draws you into its medenas and alleyways, its sepulchres and domes, grottoes, tombs and shrines.

Not since Wim Wenders' zooming in and out of Berlin in Wings of Desire has a city captured at vertiginous angles looked so arresting. The painting has a dynamism which sucks you into the city. "I don't know how I arrived at that aerial view. Maybe to detach myself from the violence on the ground," the artist says. Over the past two years, while he was sleuthing the city from its old plans and maps and painstakingly photographing it, he has been witness to murders, stabbing and curfews.

"Jerusalem is the material manifestation of something special, the centre of the world for so many. Standing on the Mount of Olives as the sun sets, it transcends tourism, which is otherwise pervasive."

A free-wheeling Buddhist who meditates, Johnson sometimes fasts and is silent for days at a time to clear his head, an exercise he says helped him to see Jerusalem clearly and to hone away the clutter.

Most artists paint Jerusalem from the Mount of Olives, that cross-roads for three religions where Christians believe Jesus ascended, Muslims that Mohammed came down to earth, and the Jews that the Messiah will arise. Johnson painted it from the other side, West to East, planting the ancient city firmly at the end of the 20th century with a gigantic car park in the foreground outside the walls. He puts all his groundwork sketches and photos into a computer model to position every building on the 15 by seven-and-a-half foot panel and to calculate their shadows. Then he outlines the buildings in section with his two assistants, painter Richard Gibson and Philip Lam, a master draughtsman, and lifts them on to the clean canvas prepared with gesso. When the paper transfers are scrubbed off, the imprint of the pencil remains to be painted by spray gun. There are no brushes in the studio.

This method, which lets the past shine through, is true to the deconstructivist philosopher Jacques Derrida's view of history as a palimpsest - a parchment on which an earlier manuscript has been erased to make a clean surface for a new one.

Sheila Johnson, the artist's wife, mixes the paints, over 300 colours of sand and stone. Over 300 photos of stones yielded the paint colours. Refreshingly unpretentious for a man with a mission, who has taken seven years (if you include his three assistants' time) over this painting, he calls it "a piece of craft with a level of passion".

The painting isn't finished yet but already Johnson is plotting ways to animate it to amuse children, with competitions to count the crosses and muezzins and Stars of David. He has decided to give Cityscapes a rest for a few years so that he can study individual buildings again. Although he won't paint "architecture as portrait" which is why he seldom accepts commissions from architects - Norman Foster was the exception - his work is snapped up by architects the world over. And he is working on a show on perspectives, with the Whitney Museum in the US, to prove that the medieval artists who laid out figures around a square, flat on their backs, really knew all about perspective. It's just that they had ignored it, since perspective wasn't needed to heighten the story.

At the Renaissance, the artist became more important than the story, and what he calls the "beginning of the colour-supplement culture with all its celebrities" began. He never signs his paintings. "I will rot away or be burnt, but my paintings will survive. The message is what counts over the centuries."