In fact, the presence of the great evangelist is so real to his grandson that the younger man still talks about him in the present tense, even though he died in February at the age of 99.

But when it came to playing the role of the man dubbed “God’s machine gun” and “Machine-gun Billy”, the fit wasn’t quite right.

“He just never quit – like, he never took a breath, he just kept going, kept going. I’m a lot more subdued than him.” – Will Graham

In the upcoming Hollywood movie Unbroken: Path to Redemption – which follows on from the events of Angelina Jolie’s Unbroken – Graham has to invoke the values and fears of another era while preaching at the 1949 Los Angeles crusade that made his grandfather famous.

“The good thing was that I didn’t have to act – I only had to do what I was naturally doing anyway,” says Graham, who is carrying on the legacy of his grandfather by holding evangelistic rallies across the globe, including Australia.

“But what was hard was I had to preach a sermon that’s not my own.”

The sermon he had to preach for the movie was entitled Why does God allow Communism? “This is 1949. The Russians had just detonated the first atomic bomb a month earlier, so the Cold War was just emerging. He would refer to ‘old Joe Stalin and his cronies’ – you know, I would never call him ‘old Joe Stalin,’” Graham says.

As well as having to memorise rhetoric that he would never use, the laid-back preacher from North Carolina also struggled to match his grandfather’s hyper-energetic delivery.

“When have you ever had anyone in Hollywood say, ‘we want [the gospel] stronger?’” – Will Graham

“They called him ‘Machine-gun Billy’ because he was so boo-boo-boo-boo-boom, he just never quit – like, he never took a breath, he just kept going, kept going. I’m a lot more subdued than him.”

Graham showed no signs of jet-lag while chatting to Eternity in Sydney on his way to an evangelistic rally in Kalgoorlie in the West Australian goldfields this weekend. Since 2010 he has held rallies in Alice Springs, Lithgow, Orange, Bathurst, Moree, Tamworth and Gunnedah, always at the invitation of local Christians.

Graham said he was excited about the clear gospel message in Unbroken: Path to Redemption, a sequel to Unbroken (2014) that tells the second half of the story of Louis Zamperini, the Olympian runner and World War II prisoner of war who came to faith when he was an alcoholic suffering from post-traumatic stress disorder.

“As a matter of fact, [Universal Studios] came back to me earlier this year and they said, ‘we actually want to make the gospel a little bit stronger.’ They said ‘we’ve already shot the movie, so we’re going to do some audio, so you’re going to go in and say these words and we’re going to overlay it with some scenes that we’ve already shot because we want to make sure that people hear a clear message of the gospel.’ When have you ever had anyone in Hollywood say, ‘we want it stronger?’ But that’s the Lord doing it, you know – that’s what’s so exciting.”

One thing Graham took away from the movie was a new sense of urgency and boldness in reaching out to rescue the many people like Louis Zamperini, who was “mad at God, feels like God’s mad at him, he feels like God’s robbing him, he’s blaming God for every bad thing in his life – just mad at life.”

“One of my spiritual gifts is I’m a crier.” – Will Graham

Though Graham feels he has lived a blessed life, with few deep sorrows, he finds it easy to empathise with those who feel let down by life and are at the end of their rope.

“When we were young, Dad took us all over the world – I’ve worked in the Middle East, I’ve worked in Africa … and I’ve been to places where hurricanes have levelled the whole city, I’ve been where people lost everything in tornadoes and so I’ve been alongside people,” he says.

“And I think one of my spiritual gifts is I’m a crier, so I sympathise. Even when I watch movies I’m going to cry. I got to sit in the back row, so no one sees me –  I’m crying all the time. So God’s given me the ability to relate to people’s pain and suffering and happiness … It breaks your heart what people go through. Just like Louis, and there are so many ‘Louies’ in life.”

Graham’s heart was first touched by the gospel when he was not quite six years old. When he went to church with his family on January 11, 1981, he was told he was too old to go to kiddies church but had to sit with the adults.

“I was kind of disappointed, as a kid would be, and I went in there and they had bread and grape juice because it was communion Sunday. I’m like, ‘man, they’ve got snacks here too. I love grape juice and I love bread! I love this church stuff.’ So when it came by, I really thought it was snacks and I reached out to get some and my dad slapped me on my wrist. I just thought he thought I was going to spill it on the carpet, so I didn’t think anything of it.

“Later that day, after lunch, Dad took me up to my bedroom and explained to me why I could not have communion because I didn’t have Jesus in my life, and then he started sharing what Jesus did for me; and so that’s when I asked Jesus to come into my life and forgive me my sins.

“I didn’t understand everything about what God did for me on the cross, but I knew I was a sinner.” – Will Graham

“Listen, I’m five years old, it’s not like I’m a murderer, but I lied, I was a thief. God wasn’t the first priority in my life, I wasn’t living for him – I knew all that. I didn’t understand everything about what God did for me on the cross, but I knew I was a sinner. I knew that I wanted to go to heaven, and I knew that Jesus died on the cross for my sin and I believed that, so I asked Jesus to come into my life and that’s when Christ did.”

A couple of years later in elementary school, the first crumb in a trail of breadcrumbs that led him to heed the call of God to preach the gospel came when he and his classmates were asked to draw a picture of what they wanted to be in life.

“Most of my friends were drawing pictures of American football players, but I drew a picture of an open Bible and a pair of David Clark headsets – headsets with a microphone, which is what pilots would use in the airplane to talk to each other and the ground,” he recalls.

“So that’s what I felt God wanted, that’s what I wanted to do in life, and so I had no idea what a calling was, it was just an inkling in my heart. I look back and I see that’s where the first seed, the first crumb in the trail started.”