I ask him what will happen if I don't. "Eternal judgment," he says. "Hell."

Mr Kephart gave his first-born son, Jonathan, to the American army. In late March the 21-year-old went to Iraq to serve with the 230th Military Police Company. Ten days later he was killed in an ambush in Baghdad.

He was the first person in Venango county, where Oil City nestles on the banks of the Allegheny river, to die in combat since Vietnam. The way his platoon sergeant, Edwin Rossman, tells it, his was a heroic death as he continued to spray insurgents with gunfire even after he had been hit twice in the shoulder during an ambush. "I know at one point when I looked at him, watching as he poured fire into the enemy troops, I knew we had a chance to make it out of there," wrote Mr Rossman in a letter to the Kepharts.

"If [Jonathan] had not been so relentless we would have suffered heavy casualties."

When the Kepharts heard the news his mother, Donna, went out to buy more yellow ribbons. Then the letters started coming in, from President Bush to the mayor of Oil City, including one from the Commander of the US European command, James L Jones, conveying his sadness at the "tragic loss of your son, Scott."

Because of the injuries Jonathan sustained, Burton and Donna were worried that there would be no open casket. But the army morticians did a good job. Now his medals and the flag that draped his coffin stand in a case on the mantlepiece, along with his Military Police band with its Arabic inscription. He has been recommended for an upgrade to a silver star.

To understand the impact of Jonathan Kephart's death on those who knew him, one must first grasp the intensity with which they believe in life after death.

Heaven, for members of the Faith Baptist church of which he and his family were members, is a real place.

"As Christians we know that Jonathan didn't fear death," says Burton, who drives a truck for Lezzer Lumber building materials. "He was saved and he's now in heaven and we look forward to seeing him again. You cannot minimise losing a son in this life. But the Lord has seen fit to take Jonathan to be with him. It was his time."

Religion dominated Jonathan's life. Faith Baptist church runs a school and a college next door, both of which Jonathan attended.

Burton sent all of his four children to the church school. Donna teaches there now, in a room emblazoned with rallying cries to God and country.

Her primary class learn writing and grammar from a book called God's Gift of Language. As I leave the class, after they had shown me the snake they caught that morning and I had told them about England, a small boy called Zeke says a prayer for my travels.

"Public schools are anti-God, anti-Bible and anti-discipline," says Burton. "We wanted to raise our children in the fear and admiration of the Lord."

So Jonathan's pastor was his headmaster, most of his friends and schoolmates were his fellow parishioners and his first employer and basketball coach, David Foote, is the pastor at the nearby Baptist temple.

Jonathan was a quiet young man who would transform into a pit bull on the basketball court. He played point guard, the linchpin of any basketball team, even though he was smaller than most.

He was a hard worker with a report card full of As and Bs and a 93% grade point average. "He's the kind of kid you'd want your daughter to marry," says Judy Toth, a former neighbour and close family friend. Mr Foote says: "He loved his country, he loved his parents, he loved his God."

But most were surprised when he enlisted in the army. "I think he wanted that discipline to help him grow up some," says Donna. Burton, who was "born again" after he came back from Vietnam, was not keen on the idea but thought it was Jonathan's decision. "I know what he was going to get into," he says. "I know what war is."

Oil City (population 11,504), formerly known as Oilville, was incorporated in 1863 because of its proximity to Oil Creek. In this part of north-western Pennsylvania, black gold once flowed freely, making the town a lucrative transport hub for oil making its way down the Allegheny river to be refined in Pittsburgh.

Today its grand Victorian architecture, including an impressive bridge over Petroleum Street, mock a decline which has put one in five residents below the poverty line.

This is where Jonathan spent most of his teenage years. While Pennsylvania went Democrat in 2000 (51% to 46%), Venango county backed the Republicans (56% to 40%). This time the state is leaning towards John Kerry, but only just and only for now. Pollsters say the economy is the single biggest issue, followed by the war in Iraq and the "war on terror".

Among those who knew him, Jonathan's death hasn't changed anybody's views on the war in Iraq. They still support it. In fact if anything, they support it more now than ever. Burton believes that those who oppose it are "un-American".

"It makes me mad, very mad," he says about those who question the war. "Jonathan believed so strongly in what he did in Iraq. I want to see it accomplished because that's what he died for. You'll never convince me that there's no connection between Saddam Hussein and al-Qaida. Never."

What is the connection? "Terrorist activity," says Burton.

They also loathe those who oppose it more than ever. "It changed the way I felt about the press," Mr Foote says. "If I hear anything negative, I take it personally. I feel that they are saying it about John. It invalidates the sacrifice he made."

And it has reconfirmed their determination to see George Bush re-elected. The Kepharts have a Bush/Cheney sign on their front lawn. Burton believes the country is stalked by evils like homosexuality and abortion, and that the election of Democratic hopeful will only compound this.

"I fear for this country if Kerry wins," he says. "God has a plan for the ages. Bush will hold back the evil a little bit. He is a God-fearing man. He believes in praying to a God who hears his prayers. He's a leader."

Such single-minded conviction about the war is typical of the political climate, says Michael Hagen, director of public affairs at Temple University in Pennsylvania. "Peoples' reactions to the war in Iraq and terrorism are shaped by their partisanship," he says. "People are interpreting these events very much in terms of their electoral preference."

Moreover, according to the National Annenberg survey, based in the state, 22% of Pennsylvania's electorate are born-again Christians.

The only person I could find who was sceptical about the war or Bush knew Jonathan but was not in his church. "I'm angry about it," says Ms Toth, the family friend. "It's such a waste. He could have been a great father, he could have been a great mission worker. Now he's dead. And for what? [The war] doesn't seem to have accomplished a whole lot."

But Burton believes that his son's final actions were a form of divine inspiration. "He could not have done what he did in protecting and defending his fellow soldiers without his faith in God," he says.

When we leave a restaurant not far from the Kepharts' house, Burton leaves a pile of scripture with the tip, in the hope that the waitress will read it and find God. Recently, after considerable reflection, he decided to write a tract on Jonathan's life and death. But for now, the one he leaves is entitled "One heartbeat away".

Next stop: Dearborn, Michigan