Thomas Cranmer’s Book of Common Prayer was well ahead of its time when in 1549 it addressed “Almighty God, unto whom all hearts be opened, all desires known, and no secrets hid” – but it would take nearly five centuries for the church to turn this vision into technology. For now there is a Church of England “skill” – a set of canned responses – on Alexa, Amazon’s virtual assistant which can give its answer to 30 religious questions. It doesn’t answer the interesting ones though. “Alexa, ask the Church of England how can I be saved?” produces a silence easily interpreted as baffled, and I don’t think this is because the Church of England long ago decided that I couldn’t be.

Religion exists to answer the questions and supply the needs that couldn’t possibly be bought with money. But Alexa is a piece of consumer technology. It exists to make it easy to buy things, listening patiently for you to express a certain kind of wish. What Amazon gets out of this deal is obvious: reliable information about which of its customers are seriously interested in the Church of England; information which can be used to sell them other things.

What’s in it for the Church, though? Obviously there is some favourable publicity to be had, in a week when the Sun printed an entire sermon across a double-page spread. There is also the hope that it will reach half-believers, or cultural Christians, who can quickly find their nearest church, or hear a prayer for the day (read by a human being and not a robot). The machine will even say grace before a meal it you ask it to. Why you should want to do so is something Alexa can’t explain.

I asked it the great question which opens the Westminster Catechism, one of the foundational documents of puritanism: “Alexa, ask the Church of England what is the chief end of man?”. The correct answer is: “To glorify God and enjoy him forever.” Alexa, though, was silent.

That isn’t really surprising. There are all sorts of questions that can reduce the Church of England to silence of polished evasiveness. When I asked “does God exist?”, Alexa didn’t give me an answer. Instead, it talked about what it feels like to believe in God, a rather surreal experience when I remembered that I was talking to a robot. “See. It’s been well briefed!” said the Church’s communications officer. But actually, it’s simpler than that. The program can only respond to trigger words and phrases which it recognises, and then only with formulaic responses.

But this shouldn’t be blamed on the Church of England. No large and respectable organisation wants to get into a theological controversy. For a second opinion I asked Google if God exists and the robot voice answered solemnly “everyone has their own opinion about religion”. Religions have always taken advantage of technology: the most obvious example is the spread of printed Bibles when printing was young; but throughout the 19th and 20th centuries Christians, and especially missionaries, made use of innovative techniques to get the message out. The word “propaganda” itself originates from the Vatican, while evangelical Christians worked on hymns that would embed their message in unforgettable tunes. In the 20th century it was the American religious right that invented database marketing, while the merchandising skills of charismatic megachurches are almost up there with Disney’s.

But the established churches have been incredibly slow to understand the digital revolution. The online deconstruction of authority which we have seen in politics over the last 10 years is an echo of the same loss of central control that had happened in the big Christian denominations in the years before. Fake news flourished on far-right religious sites before it crossed into the mainstream, and international alliances against the liberal order were being formed to destroy the Anglican communion long before the wider world had heard of Trump, Farage, or even Putin.

The Vatican’s website is still a confusing mess, whereas the unofficial websites which agitated for Alfie Evans were slick and forceful. So the emergence of this Church of England Alexa skill really is a surprise. Obviously, everyone else will have to retaliate. The Humanists, the Muslims, the Catholics, the conservative evangelicals and even the Richard Dawkins Foundation will have to launch their own Alexa skills. Google and Siri will get in on the act as well. It’s all invaluable marketing information, after all. The resulting cacophony of canned replies will be indistinguishable from what passes for religious debate online today, but no one will have to type to participate; they can simply speak into the empty air.

• Andrew Brown is a Guardian columnist