The York Mystery Plays, Museum Gardens, York

Is it the greatest story ever told, or the most indulgent nativity ever staged? The return of the York Mystery Plays – this summer’s blue-ribbon theatrical spectacular in the North – begins by beguiling, ends up bemusing, while in between is a sacred story about the eternal battle of good and evil, from Creation to the Last Judgement.

The timing of this showpiece alone is enough to make its mark on a 700-year-old heritage in York. As birds flutter over a pink, cloudless sunset, a sense of history is not lost on a crisp-crunching, wine-guzzling audience, who take their seats, prepared with blankets for the evening. The Plays were once paraded through the streets of the medieval city, the earliest known performance dating back to 1376. For hundreds of years, they were a method by which Christian messages were transmitted to the public, continuing until the early Reformation. Since the revival of the tradition in 1951, there have been regular stagings of the Mysteries, the most recent falling during the Millennium celebrations.

Directed by Paul Burbridge and Damian Cruden, this latest addition to the cycle – performed at York Museum Gardens for the first time since 1988 – has been adapted by Mike Kenny, the playwright responsible for Theatre Royal York’s Olivier Award-winning The Railway Children. Ferdinand Kingsley (son of Sir Ben) plays God and Jesus (pictured right), opposite Graeme Hawley – former Coronation Street villain John Snape – as the Devil.

The bespoke, 1400-capacity auditorium houses a multi-layered set of smoke-billowing trapdoors and spotlit platforms. Some minor pyrotechnics, a 97-strong choir and an array of giant balloons guide the audience through the opening scenes – including the Garden of Eden, which includes dozens of merry hedge-trimmers on bicycles. Christopher Madin’s cinematic score is perfect acoustic foil for the hyperbole on stage, and, at times, the choreography and directing is bedazzling. The costumes are impressive, too: Mary wears a headscarf and Joseph a flat cap as the biblical narrative sets itself in post-war Yorkshire. Lines such as "Nae Noah, I am not best-pleased” provoke laughter among older members of the audience.)

Yes, visually, it is stunning, majestic, superb. But there comes a time when, perhaps as the midges begin biting your skin, you realise that any sort of intellectual stimulation isn’t going to happen, because this is essentially an extravagant summary of the Old and New Testaments. Towards the end of Act One, families sitting near me were shuffling uncomfortably, teenagers rolling their eyes and tapping on their phones. There’s something formulaic about the way large swathes of cast assemble and disperse en masse at the end of each scene, and a lack of chemistry between some of the performers, whose hundreds of names run four pages long in the programme.

As the evening proceeds through the Last Supper, the Crucifixion, and… you know what happens next, the colossal effort that has gone into the York Mystery Plays – the 2500 people involved, the hours of rehearsal time, 1400 metres of cabling required – is somehow let down by the greatest story ever told itself. Even with the Yorkshire-tinged embellishments in Kenny’s script, the dialogue offers little to engage a modern, mostly atheistic audience. For all the project’s seductive grandeur (more shows to be staged here, please) it feels like an opportunity missed.

• The York Mystery Plays at the Museum Gardens until 27 August