A local elder stands up and shuffles his way to the microphone. He is in his eighties, at least, and looks pale and fragile, like a drift of smoke. There is a squeal of feedback. He clears his throat. The sound of it bounces off the parquet floor.

‘Ladies and gentlemen,’ he says. ‘Without further ado, it gives me great pleasure to, er, be able to introduce to you a man whose work I’m sure you’re all familiar with. We’ve been looking forward to his talk for a long time now. He’s, er, travelled a long way to see us tonight, so please give a very warm welcome to Mr John Mackay.’

Proudly, down the centre aisle, I watch him come: the man we all want to see. With his white prophet’s beard, charismatic glimmer and wide-brimmed bushman’s hat, he clutches in his right hand a thousand pages of visions, violence and lore, of science, sects and sorcery, all the wisdom of all the worlds, everything anyone needs to know about anything. Mackay walks slowly through applause, takes his place at the front of the hall and waits for the crowd to settle. Once silence is regained, he finally begins.

‘Charles Darwin wrote a book,’ he announces. ‘Does anyone know what its name was?’ His sparkly eyes scan the rows. ‘The name of his book was The Origin of the Species. I have another book here.’ He holds up his leather-bound volume, its pages, weary at the corners, flop open. ‘It’s called the Bible. Tonight, the choice you have to face up to is this – do you put your faith in Darwin, who wasn’t there? Or God, who was?’

As Mackay speaks, the hands of the church clock, down in the town centre, clunk to 8.30. By now, the place is almost entirely deserted. That is what it is like up here, a hundred and sixty miles north of Brisbane, Australia, on the humid banks of the Mary River. It is a place of early closing and close community; of pineapple plantations, clapboard churches, empty roads and old Holden Utes rusting in silent fields. The landscape itself is lush and strange, with its sinisterly christened creeks, monster cacti growing in gas station forecourts and vast rock formations that jut out of the land like ancient tumours. The locals – dairy farmers, timber men and the descendants of gold-rush pioneers – know the town as Gympie, an Aboriginal word meaning Devil. It is actually named for a freakish native tree, a murderous hermaphrodite called the gympie-gympie, whose flowers are simultaneously male and female, whose fruit is a lurid, tumescent purple and pink and whose pretty heart-shaped leaves are covered with hairs that contain a toxin noxious enough to kill dogs, horses and sometimes men. The gympie-gympie is a hysterical nightmare of nature; evidence, I believe, of the conscienceless magnificence of biological evolution. But, right here, right now, I am in an intimidating minority of one. Because all of these people and tonight’s main attraction – an international Creationist superstar and tireless prosecutor of the diabolical trinity Darwin, Dawkins and Attenborough – believe the gympie-gympie’s malevolence to be a direct result of Adam eating forbidden fruit and introducing sin, death and nasty prickles to a perfect world.

Mackay clicks a button. An image of an enormous bird flashes on to the overhead projector.

‘What’s the name of that funny little chicken?’ he says.

Nobody responds.

‘Emu!’ he says. ‘They can’t fly, but they can run like crazy. The interesting thing is, if you dig up their fossils, they used to be twice the size they now are. That’s change, but it’s not evolution.’

He allows the last sentence to unfurl slowly in the sweating air above him.

‘If you take your Bible seriously you will notice that Genesis is emphatic that when God made the world there were no killers. Everything only ate plants. Now that is different to Charles Darwin’s picture of evolution. Genesis one and two are dogmatic. God made everything very good. Do you realise that means there was a world where even broccoli tasted good? Can you believe that? That’s what it’s talking about. It meant no killers, no carnivores, no competition and no struggle to survive. But what is that catchphrase you learned in biology at high school? Survival of the …? Fittest. But no such competition occurred back in God’s world. There was no struggle to survive at all. Everything survived.’

Mackay presses his little button again and the famous silhouette depiction of ‘the evolution of man’ appears.

‘You see the chimpanzee on the left?’ he asks. ‘You see the man on the right? That’s the history of the world according to most high-school textbooks. You and I are just hydrogen and somehow or other we turned into people. But if you look at your Bible, it says that everything started perfect and went downhill. Man sinned, God cursed the ground and death entered the world.’

He turns to face his screen.

‘Let’s put that in diagram form.’

On the screen, a bar graph appears, consisting of biblical names and numbers.

‘Do you know that Adam lived until he was nine hundred and thirty years old? Noah lived until he was nine hundred and fifty? Abraham drops off at a hundred and seventy-five. Anyone here a hundred and seventy-five tonight? No? Big difference in the world. That’s change, but it’s not evolution. We live in a world where life-spans are influenced by stress in the environment. I’m old enough to remember when the Vietnamese first turned up in Australia. They were tiny. They’d come from a nasty place. All they’d had to eat for fifty years was bullets and Americans.’

I shift restlessly on the hard wooden seat, my eyes settling for a moment on a blank page in my reporter’s notepad. I see the lines there, ready to be filled with the descriptions and the strings of overheard dialogue and the thoughts that I’ll think about these Christians, these crazy Christians; the words that will make up the story that will eventually be read by people just like me. I see the lines, and I already know what they’re going to say.

Sighing, I glance down the row. I really am a very long way from home. It is as if I am in a rural town of the early 1950s, listening to the shibboleths of men from the 1400s. Strange to think that we are comfortably inside the twenty-first century, and John Mackay is neither a time traveller nor an idiot of the fringes. Rather, he is a famous Christian figurehead who has just flown in from a tour of America and Britain, where he has spoken to thousands of fellow believers and appeared on mainstream television shows. A veteran evangelist for the literal truth of Genesis – the book of the Bible that describes God building the earth in six days – he has come to north Australia to give a talk on the obsession that has run through his life like a burning wick: evolution and all the reasons it is wrong.

For Christians like Mackay, this is the Armageddon debate, the row to end all rows. Its logic is stark and indestructible: to accept evolution, they say, is to call the entire Bible a lie. Anyone who successfully proves that God didn’t create the earth in six days is setting off a chain of explosions that starts at the very base of all Christian thought; bursts up through the architecture of its parables, prophesies and gospels; and ultimately blows off its roof in a vast Satanic mushroom cloud. ‘How do you get rid of God?’ Mackay asks. ‘You can’t shoot him dead. So you attack his authority – and his authority is that he created the earth.’

Indeed, Mackay believes that if Lucifer himself didn’t come up with the theory of evolution, he is certainly behind its wild successes. ‘You have to look at the theory of evolution as the basis of all anti-God morality in the West,’ he says. Later, when I ask him whether he considers The Origin of Species to be ‘a kind of Satanic version of the book of Genesis,’ he brightens, pleased by the analogy, and says, ‘Yes, definitely. That’s exactly what it is.’

Mackay’s organisation, Creation Research – whose stated aim is ‘to seek evidence for the biblical account of creation’ – has offices in the US, Canada, New Zealand and the UK and his annual speaking tours have made his name notorious among those familiar with the debate. In the last few years, he has earned attacks from august scientific bodies such as the Royal Society and the British Centre for Science Education, which has even gone so far as to publish an MI5-style dossier on Mackay (‘Appearance: Mackay likes to play the larrikin. His dress style could best be described as “outback casual”’). In 2006 the National Union of Teachers demanded new legislation to outlaw Mackay-style school creationism lessons, which the National Secular Society described as ‘verging on intellectual child abuse.’

When I sat myself down in the community hall, I was unaware of the full strangeness of the creationists’ theory. Luckily for me, Mackay proves to be an excellent teacher. I learn that around six thousand years ago, when God made the earth in six days, the environment was perfect and, as a result, Noah had metre-long forearms. There was no suffering, struggle, illness or sorrow; there were no carnivores; all living things grew enormous and the temperature was permanently pleasant. But ever since the day that Eve allowed a snake to talk her into eating the apple and then shared it with Adam, the world has become harsher, its inhabitants have got smaller and sicker and human society has been thrashing about in ever more desperate throes. God tried to teach us a lesson when he made it rain for forty nights. We didn’t learn. We are incapable: ever since Eve’s crime, we’ve been born this way – outlaw failures, fucking and sinning with callous abandon as the planet we’ve been given withers around us.

As his talk progresses, two further facts become apparent about John Mackay. One, he likes to speak in questions. Two, he has a bit of a thing about David Attenborough. ‘I know a question David Attenborough wouldn’t ask,’ he says at one point. ‘If creation is true, what would the evidence be?’

Of all the questions ever, this is probably John’s favourite because he believes that the evidence is on the side of God. By education and by thinking, Mackay considers himself to be a scientist. And it is by these rigorous and testable methods that he has promised to prove the creation hypothesis to me.

When his talk is over, the Gympie Christians begin to bumble out of the double doors, with a few getting snagged on small talk and lingering in chatty knots here and there. It is obvious that nobody had a real problem with John’s presentation. He was, literally, preaching to the converted, and his audience reacted to what he had to say in exactly the manner you would expect of a people who were, in effect, sitting through a six-thousand-year-old news report. The only person I can find in the crowd who isn’t wholly convinced is a young woman named Catherine Stipe. She admits to doubts about some aspects of creationism before quickly adding, ‘But as long as God made everything I’m happy.’ When I ask if she believes in evolution, she looks baffled. ‘I wouldn’t quite go that far.’

As the hall empties, Mackay patrols his merchandise – books, DVDs and fossils and crystals which are, according to a sign, useful both for demonstrating ‘God’s engineering genius’ and ‘combating new age lies’. Several of the DVDs are of debates with evolutionist academics, which poses an interesting question: If evolution is so demonstrably true, what is he doing debating with academics and then selling the resulting showdowns in sumptuously produced DVD twin packs for $50 a go? What is he doing behaving like a man who is winning?

‘We frequently win public debates,’ Mackay tells me when we sit down later on. ‘In fact, for a long while it was impossible to get debates because the academics didn’t want to be shown up. But then word went around, “They’re making too much progress, we’ve got to debate them again.” So in the last few years we’ve had quite a lot and the reason they always fail to beat us is they presume they’re fighting against theologians with no science degrees.’

Mackay, a geologist and geneticist who seems to possess an eager and audacious intellect, has most recently crossed ideologies with iconic atheist Professor Richard Dawkins – who, not incidentally, once told the Guardian newspaper, ‘People like Mackay thrive by drip-feeding misinformation … we cannot afford to take creationism lightly. It’s not an amusing diversion, but a serious threat to scientific reason.’

John recalls the meeting with a contemptuous sigh. ‘He was trying to be David Attenborough,’ he says. ‘I think it’s because he’s been getting so much flak. People are sick of him. Do you know, if Dawkins is speaking at a university before me, the evolutionists get so disgusted with him they’ll double my crowd? But I led him to a point where he said, “Evolution has been observed, it just hasn’t been observed while it’s been happening.” And that’s just a stupid statement. If it...