This was not an especially controversial Synod. The Church's two (literally) sexiest issues were both, very temporarily, off the agenda: women bishops and gay priests. The press officers seemed a bit surprised that I had nothing better to do with my own Saturday night.

But the issue under discussion was far more important than either controversy. Indeed, it was absolutely fundamental to the future of the Church. In 40 years, attendance at Church of England services has halved and, according to the latest figures, is still falling: down to 1.13 million a week, barely 2 per cent of the population. Among the young, the drop is said to be 80 per cent.

"We are faced with a stark and urgent choice: do we spend the next few years managing decline, or do we go for growth?" asked the background paper accompanying the motion. Indeed, we all face a similar dilemma individually. Do we surrender to the ageing process or try to rejuvenate ourselves? We all know the answer we want, but how - in heaven's name - do we achieve that? The task for the Church seems every bit as hopeless.

There was not much to argue about. The motion called for a "national mission action plan" to try to reverse the fall in attendance, and was carried by 333 votes to nine. The only argument against was that a national plan was unnecessary and that the individual dioceses should get on with the job.

National plans are a bit unAnglican. England has had more than 300 years of religious harmony because the Church's faults are also its virtues. It is placid, adaptable, non-doctrinaire. It fits the nation's self-image: we compromise and we muddle through.

The Church's system of governance is chaotic: at local level, the bishop is in charge of his diocese but has no power over his HQ, the cathedral, run by the dean and chapter - a recipe for disaster in theory and, sometimes, in practice. There is frustration at national level too. "If you could change one thing about the church?" Rowan Williams was asked in a recent interview. "Rethink the General Synod," he replied at once.

Indeed, the Synod - led by its lay members - has lately proved unusually uppity. At York, it rejected a scheme to bring in fixed (and higher) charges for weddings and burials and also forced a retreat by the nominated candidate for chairman of the business committee: the Bishop of Dover, who was seen as too close to Canterbury, geographically and otherwise. The rebelliousness is thought to be partly linked to the Church's terrifying pensions deficit (an estimated £350m) and the sense that ordinary churchgoers will end up funding it.

Yet confrontation is usually averted by the Church's essential good nature. To an extent, that comes with the territory: the Church can hardly make even a visiting journalist feel unwelcome. And the habit seems to have been enhanced by the character of the current archbishop. His predecessors are always referred to by their surnames: Ramsey, Coggan, Runcie, Carey, making them sound like the defensive line-up for a lower-division football team. This one is always "Rowan". That may be the new informality. It may be because most of us only know of one other Rowan. It may also reflect a genuine affection. But is affection enough to save the Church of England?

The next day, the Third Sunday after Trinity, formality did reign. The archbishop led the way, dressed in a gorgeous green ("to mark the season", I was told) for the special Synod Eucharist at York Minster. The building was packed; the choir was on top form. Just before the Sacrament, everyone recited the Nicene Creed: "We believe in one God ... one Lord, Jesus Christ ... eternally begotten of the Father ... incarnate from the Holy Spirit and the Virgin Mary ... crucified ... on the third day he rose again ... ascended into heaven and is seated at the right hand of the Father ..."

Two days earlier, I had been in Durham Cathedral for choral evensong, where the crowd was altogether smaller though the service - to my ear - even lovelier, including Harold Darke's arrangement of the Magnificat in A Minor. The Creed there was the Apostles' Creed, from The Book of Common Prayer, which is subtly different and less sanitised, adding the detail that Jesus spent three days in Hell, as if on remand, before ascending to his Father's right hand.

Looking round the Minster, I wondered if the highly sophisticated and intelligent people reciting the Creed really believed everything they were saying. Everyone was in full voice; I failed to spot anyone with their fingers crossed. But the answer seemed to be: not exactly.

"What we're doing is identifying back to a distant past," explained Michael Sadgrove, the Dean of Durham. "When we say he descended to Hell, I think, if people identify with it at all, they're identifying with a tradition. The Latin for Nicene Creed is Symbolum Nicaenum. And I think these statements of faith have a symbolic function.

"I don't think the way to understand them is to dissect them clause by clause. The fundamental of Christian faith is that Jesus Christ is our Lord and Christians will argue for ever about how you put boundaries round that." It was a former bishop of Durham, David Jenkins, who most clearly, and controversially, articulated the revisionist view of gospel truth. His heirs are more circumspect but not necessarily in major disagreement.

Not many now believe Heaven and Earth were created in six days. And, in the words of Christina Rees, a lay member of the Archbishops' Council: "There are very few Anglicans who believe that God zaps planet Earth when there are a few too many gay orgies." Like all authority, the Church maintained its grip by a mixture of promise and threat: do as we tell you and go to Heaven; disobey and it's Hell. When that fades, it has a much harder job.

The world's religions are in general turmoil. Catholicism was in crisis across Europe - its teachings on birth control simply ignored - even before the paedophilia scandals. Diaspora Judaism is in demographic meltdown as its sons marry out of the faith. Islam is in the worst crisis of all because adherents of different branches are killing each other in the name of the deity, in a way that Christians gave up four centuries ago. Anglicanism's problems are less dramatic but more intractable.

There is, however, a peculiar delight to be had researching this subject. It seems to me no coincidence that so many English churchmen enjoy cricket, another field of activity which offers the pleasures of aesthetics, arcana and anomalies (not to mention an inscrutable umpire to deliver a final and immutable verdict). Anyone with a certain cast of mind can easily become fixated on the exact difference between a canon and a prebendary.

The English still love old churches and even the unbelievers will get agitated if they are threatened. (As Churchill reputedly said: "I'm not a pillar of the Church, I'm a buttress. I support it from the outside.") Cathedrals are especially popular, with good reason. And their services have actually become more popular in recent years - why go to the local am-dram if you have the ecclesiastical equivalent of West End theatre only a short drive away?

For instance, Durham Cathedral, perched defiantly on its hilltop, is one of the outstanding buildings of the world - never mind England. But, unlike some of its southern equivalents, it does not attempt to charge admission, even though it needs the money. In part, that's a matter of principle, says the dean: "You can't ever know why people are there." Even the sternest pay-up-or-elsers such as St Paul's (£14.50) and Ely (£6.50) try to avoid fleecing genuine worshippers.

But it's also a question of demographics. A high percentage of visitors are local, and the cathedral is fearful of upsetting them. Historically, the church here, ruled by Oxbridge men, has had a complex relationship with the industrial working class who populated the area. Many of them found Methodism more egalitarian. "You could go a long time without hearing anything other than a local accent," said Tom Thubron, retired vicar of the old pit village of Wheatley Hill. "Except from the pulpit."

Thubron was an exception: a shipworker and merchant seaman who found his vocation when he was 30. He then spent 12 years as a missionary. Before he went, churchgoing was still part of a child's routine, as was Sunday school. "That was partly because if you lived in a two-bedroom cottage with a lot of kids it was the only time in the week mum and dad could go to bed together in peace. But it was part of people's lives. Fifty years ago, there would be five charabancs for the annual Sunday school treat. When I came back, in 1980, that had all gone. We might still get 30 for the Sunday service, but hardly any children."

Across the diocese, some of today's vicars have to work extra hard to catch up. Reverend Richard Deimel arrived last year from Warwickshire to take over five parishes - a normal workload these days. He has two big advantages: firstly, his wife, Margaret, is also ordained and helps out, unpaid; secondly, his home parish of Escomb has an astonishing church: an almost perfect Saxon building where services have been held since about 670 AD, perhaps 50 generations ago. Contemplating that is like contemplating the ineffability of God.

Even so, he has a tough job. All summer the Deimels have been holding sessions called "Celtic Springs": meditations, chanting, celebrations to mark the ancient landmarks such as midsummer and Lammastide (August 1). It's an attempt to touch feelings that predate the church in potential worshippers the vicar describes as "post-church".

He has a role in the diocese involving new spiritual movements ("like what to do if someone turns up and says, 'I'm a witch but want to come to church', which does happen"). "People are put off by hierarchies," says the vicar. "They want to be spiritual but not under authority. Our job is to be in the community where they are, rather than getting them to come to church."

Just down the road, Reverend Brenda Jones is trying to put that even more spectacularly into practice at Woodhouse Close, a tough estate on the edge of Bishop Auckland, said to have the second-highest teen pregnancy rate in Europe. Her church is not Saxon (it's in the postwar Barbarian style) but, in partnership with the Methodists, she immerses herself in the problems of the area. The church-run community centre offers a credit union, thrift shop, furniture collection service, lunch club, meals on wheels, baby and toddler groups, youth drama... "We've been doing the Big Society for 50 years," she says.

"The problem is that we have such a low economic base we can't generate the finance. We've got pockets of funding that will last for about three years, but I don't know where we go in the future." Is this what the church ought to be doing? "It's seeing every person as a person of value, and that's what Christ taught."

. . .

And so across the country - across the vast spectrum of Church of England style, from incense-burning High to happy-clappy Low - enthusiastic priests and congregations try to fulfil their own mission action plans. In the little Norman church at Farleigh, Surrey, there are Sunday cream teas and then compline-by-candlelight with guest speakers. In my own very rural part of Herefordshire our vicar, Nicholas Lowton, borrowed a donkey for Palm Sunday. A week later, Easter Day, he led his congregation on the stiff climb up Black Hill, our own Mount of Olives, and was rewarded with a turnout of 60. Religion always works best when it remembers it is first cousin to theatre.

The benchmark for this approach is the west London church of Holy Trinity, Brompton (so famous it's known as HTB), which is in a totally different league. This is the birthplace of the Alpha courses in basic Christianity, reputedly attended by two and a half million people in Britain alone over the past two decades, and 15 million worldwide. Alpha reaches way beyond Anglicanism to places cream teas and donkeys cannot reach.

HTB operates with complete propriety inside the Church of England but there is about it just the teeniest whiff of a cult. There are worse dating agencies for the young, lost and lonely in the city. It offers them fellowship and a degree of certitude. The rest of the Church looks on with a mixture of admiration, jealousy and wariness. "They do very good work," says one observer. "But they grip you a bit too firmly by the hand, their teeth are a bit too white and their smile a bit too wide."

But certitude is what most of the Church of England so palpably lacks. The trumpet gives an uncertain sound. And no one embodies the tortured doubt more than its leader. Rowan Williams can perhaps be seen as an ecclesiastical Obama, a beacon of hope for the liberals who has turned out to be a pragmatist/compromiser/prevaricator (delete to taste) without ever quite losing the admiration of his original constituency.

Nearly 20 years after its first women priests, the Church of England is inching towards its first women bishops. The crucial vote is due at the 2012 York Synod. The ginger group Reform (inappropriately named, say its opponents) still talks about "the divine order of male headship", but the argument is now about the terms of surrender and whether the arrangements made to pacify the refuseniks will stop them marching off towards Rome.

Christina Rees (who is, understandably, pro-women bishops) conducts a sort of Punch and Judy show on platforms with a leading opponent, Prebendary David Houlding: "He's a friend of mine," she said. "He's stayed in my house. We often have the same views." But not on this.

"There's nothing in scripture that supports women bishops, rather the opposite," Houlding insists to me. "Jesus had a radically different view of women compared to the society around him. But he did not choose them to be his apostles."

"But everything's changed," I protest.

"So what? This is not about the place of women in society. It's about how Jesus shaped his church."

"We cannot put ourselves into the mindset of first-century Palestine," responds Rees. And she refers me to the 16th-century debate that convulsed the church in Germany: "Are women human?"

But the issue that really convulses the modern church, almost obsesses it, is that of homosexuality. It isn't a secret that a lot of the clergy are gay: Stephen Bates, in his book A Church at War , guesstimated the figure, in cities anyway, at 20 to 25 per cent. The race has been on to see who would become a bishop first: a woman or an openly gay man.

Uneasiness about homosexuality, however, unites some of the conservatives, Anglo-Catholic and Evangelical, who might not agree on much else, and attracts many moderates, too: "You can't suggest that anything goes," one small-town vicar said to me. "There has to be a line." This last group appears to include the archbishop, who has lately tried to park the issue by saying that gay clergy are OK, if they remain celibate. Which is parking the issue not just on a double yellow line, but in the fast lane of a motorway. There's bound to be a crash.

However, the real dilemma is that Anglicanism is not just about the million or so English churchgoers or even the 20 million who call themselves Church of England when pushed. There are more than 85 million Anglicans worldwide, and 20 million of them are in Nigeria, whose leaders are appalled by tolerance of homosexuality.

There is a fairly easy way out: bash out some hypocritical English compromise and let the Africans go hang. But in his presidential address to the Synod, Rowan Williams took wing when he talked about his visit to the Congo, where he had spoken to young soldiers forced to commit atrocities: "One after another, they kept saying, 'The Church didn't abandon us,'" he reported.

And one can see that, although Anglicanism may touch barely one per cent of the world, it is the lingering sense of universality that gives it what bite and purpose and dynamism it still has. Its problems need to be resolved in a global context; in the words of Paul Handley, editor of the Church Times, "You can't have a Surrey solution". The Church has to be about improving life here on Earth, and not just a bet on the existence of Heaven.

"If, at the end of my life," said Tom Thubron at Wheatley Hill, "there's a kind of blind coming down and that's all there is, I wouldn't have thought I'd have wasted my time. It isn't that religion has made me holy. But it's kept me honest with myself. I think my influence has been in trying to make the world better. And that in itself is worthwhile."

END