JUST before the final episode of the BBC2 series Rev this week (News, 14 March; Features, 28 March), a friend wondered where the sitcom could go, after the dramatic penultimate episode, which was set against the background of Passiontide. The answer, it turned out, was obvious. The final episode dealt with resurrection, which, it emerged, was far from the same thing as a happy ending.

This comedy series about a kindly bumbling vicar coping with the unending problems of a deprived inner-city parish has become something of a surprise hit over the past four years. In the run-up to last night's final episode in the show's third - and possibly final - series, it has amassed 1.7 million viewers.

It has been a good advert for the Church of England, and for faith in general. Its stumbling hero, the Revd Adam Smallbone, has been brilliantly played by Tom Hollander, who is also one of the writers of the script. He and his co-writer James Wood have clearly been assiduous in their background research. The series touches the pulse of church life with disturbing accuracy.

This has offered a rich vein of humour, affording everything from wry eyebrow-lifting smiles to outright squealing belly laughs. But non-believers have also learned some unexpected truths about how a parish priest's door is ever open to the most motley callers - from middle-class parents seeking a place at a church school to inner-city waifs and strays.

What makes Smallbone a heroic figure is that he blunders his well-meaning way through all this without hiding his struggles with doubt. And, refreshingly, Rev is a rare commodity in modern television because it deals with Smallbone's relationship with God in a direct and uncyncial way. The interior monologues of the protagonist - and, indeed, everyone in the final episode - were presented utterly without the sneering that seems de rigueur in contemporary metropolitan culture.

Towards its end, Rev developed in an interesting way. It began as a comedy with serious elements. But it became something more complex and profound. This left some viewers baffled. One asked last week: "Is it a comedy, a drama, or a soap? It has humour without being silly, and the main character evokes sympathy, but he is quite half-hearted for a vicar. . . Is it meant to have a serious point?"

It certainly is. In this past series, Rev has made the transition from observational comedy to what, since Gabriel García Márquez, we have learned to call magic realism. It began subtly, with the echoes of the Last Supper in episode 4, and became more pointed.

In episode 5, a slightly febrile Smallbone took it upon himself to deliver a life-size cross by carrying it through the streets, in an episode that became hallucinogenic, and ended with Liam Neeson making a guest appearance as the kind of Jesus who would have been at home in an episode of Shameless. In the final episode, all the main characters gather for an Easter vigil, in a plot twist that defied everyday logic, but which was freighted with transcendent symbolism.

"Is this what resurrection is?" the hero asks, before he sings the Easter Exultet with a breathless beauty. It was not a happy ending, but it finally rejected the suggestion that the series had seemed to be outlining, that you can survive in the Church only if you are a conformist, careerist, legalist, pedant, or hypocrite. The light of a weak dawn flickered, but it offered the prospect of a new start. And perhaps that is all we can hope for.