David Self enjoys a compelling guide to the politics, feuds and embedded hatreds that now characterise our national church.

For some years I chaired the governors of a small Norfolk voluntary-aided Church of England school. When, after 40 years, we eventually got indoor toilets, our bishop came to help us celebrate. Every Wednesday the rector spoke at assembly. Each Ascension Day, we trooped off to a service at the parish church. Otherwise the national (still less the worldwide) church made little impact on us.

Nevertheless, there was quiet satisfaction in the village that ours was a church school. The brand image still plays well; parents choose houses to be within the catchment area of such schools. Their ethos and results are perceived as “better” than local authority ones. Now, however, the patronage of the Church of England for its schools is in doubt - because the future of that church is so uncertain.

This is not because it is shrinking so rapidly, with fewer than a million people now attending its Sunday services. It is not because more than half its dioceses are running deficits, nor because (with half its clergy now retired) it is facing a crippling pensions bill. It is not even because, one day, it may have to marry the heir to the throne to a woman with whom he has had an adulterous affair. It is because one drizzly afternoon last autumn in the ice hockey stadium of a small New England town, a sister church consecrated as its bishop a priest who is gay.

How a church created because Henry VIII wanted someone else in his bed rather than Catherine of Aragon and which has since embraced wildly opposing beliefs and practices should now be facing disintegration over the gay question is the story told in Stephen Bates’s new book.

The Guardian’s church affairs correspondent tells this hilarious and depressing story with asperity and wit. Introducing us to the Archbishop of Canterbury, Rowan Williams, he describes him as speaking well and being “a writer, poet, linguist and extremely brainy”. He goes on to explain how he became Archbishop “despite these drawbacks”.

The battle within the Church of England mirrors the greater one between the various autonomous provinces that make up the worldwide Anglican communion.

On the one hand are the liberals, edging towards a public acceptance and (occasionally) a celebration of “permanent, faithful, stable” same-sex unions and believing that the Bible on which their faith is built should be interpreted for each age. On the other hand are the traditionalists, mainly evangelicals, for whom the Bible is God’s word for all time and for whom homosexuality is a sin.

In an interview given to the author for the book, Rowan Williams suggests why this unlikely topic should be the one to split the church. “It’s not something that affects many people, unlike divorce. It’s a good rallying point at a time of cultural flux. If you are a Catholic, there are other issues you can find as a marker - divorce, contraception - but Anglicanism does not have these.”

Despite the arcane politics of Anglican infighting, Bates shows how the various evangelical groupings have been increasing their power base within the church’s parliament, the Synod, and how meticulously they have planned to use this issue as the one on which they will not budge.

They have found powerful and numerous allies in the evangelical churches of west and east Africa (there are 17 million Anglicans in Nigeria) even if these fellow Christians are not to their taste. The editor of the English evangelical quarterly, Churchman, wrote last year that he would prefer a black bishop to a gay one “even if he may look more like the church janitor than like any of his worshippers”.

For those on the periphery of the church, this may seem a sad and irrelevant battle. After all, the tide of history (and social change) is against the evangelicals - although this fact confirms them in their belief that they are right to stand firm. But they are now highly influential, holding many of the church purse strings as well as the political high ground. As a result, a number of headteachers of church-aided or controlled schools have already had to learn to live alongside evangelical vicars with strong opinions. And, as the ongoing conflict repeatedly hits the headlines, there can be few RE teachers who have not faced questions about gay bishops and gay marriage.

For such teachers, this is an excellent guide to the party politics, feuds and embedded hatreds that now characterise our national church. Bates relishes the plot and tells it with the immediacy of good journalism. All that remains is for the final act to be written.

That may focus on the report of a church commission now exploring this conflict. Bates believes this commission will “prize unity above truth and justice”. In other words, the gays will be hung out to dry. The result will be a narrower church which, Bates suggests, “will decline and die in the West”.