He modelled himself on his German grandfather, who had been in the SS, the black uniformed elite corps of Hitler’s Nazi Party.

“There were pictures of him in his uniform and so I went down that road. I was very racist, very hateful against everyone. I was angry with the world and this was a road to go down to express that,” he says.

Rob and Tianne Varicak with children in South Sudan. Rob Varicak

“I wouldn’t even eat Asian foods and I would scream at my parents for making those foods.”

He couldn’t read well when he left school in Geelong, Victoria, and, unable to get a job, he fell hard into the drug and party scene with his mates.

“You need money for partying and drugs, but you haven’t got a job and it’s a natural progression to get into crime,” says Varicak, now 43.

“I would jump the back fence so I wouldn’t have to go through the lounge, which was full of Christian people praying.”

The young Varicak was arrested several times for breaking into warehouses and other petty crimes and was fortunate to escape jail.

His problems persisted into his mid-20s when his brother Shane came to faith in Christ through reading C.S. Lewis’ The Chronicles of Narnia.

“I was wondering why he threw out all his gangster clothes and started dressing in linen and seemed to be getting his life in order,” Varicak recalls.

“It was talking about wars and violence and bloodshed and a whole tribe being annihilated and that was what I was into at that time.”

“He used to have Bible studies at my house. I would jump the back fence so I wouldn’t have to go through the lounge, which was full of Christian people praying. I know they were praying for me.

“My brother and I would have fights, we’d grab each other and I’d call him derogatory Christian names. He would say, ‘But, bro, I still love you.’ And I think it’s a great picture of what we’re supposed to do as Christians, just to keep hanging on.”

One day he entered his brother’s bedroom to look for something and noticed a Bible. He picked it up and began flicking through, then started reading from the beginning of the Old Testament.

“It was talking about wars and violence and bloodshed and a whole tribe being annihilated and that was what I was into at that time,” he says.

“I thought ‘Wow, this isn’t what Christianity is supposed to be about!’

I thought there’s something weird, contradictory here. I just kept reading that Bible for about two years; I’d come home and I’d be stoned and I’d get drunk and I’d lie on my bed and just read until I fell asleep.”

Tianne with children in Doro, South Sudan. Rob Varicak

When he reached the New Testament his eyes were opened when he read verses about being a child of God and being called and chosen by God.

“All of a sudden it was like my own thought in my head – I know now it was God’s quiet voice – ‘You need to get off the drugs, don’t tell your mates where you’re going and just go.’”

Varicak sold his possessions, switched off his mobile phone and headed north in his V8, taking with him a gun with a single bullet in it just in case.

“So I went to the church and into his office and again I started crying; I just couldn’t stop.”

When he reached Darwin he got a job as an upholsterer in a motor trimming company and quit drugs. But he still felt “weird, empty and lost” and longed to go back to his old mates in Geelong.

God had led him to get rid of his gun, but he bought a compound bow and decided to join a hunting club. As he searched the Yellow Pages listings he reached churches before he got to clubs and felt an impulse to ring up a church.

“Rev Rob Tan answered the phone and I started crying convulsively. I don’t remember ever crying, not as a child, getting into fights, getting hit over the head with a baseball bat.

“So I went to the church and into his office and again I started crying; I just couldn’t stop.”

The emotions were triggered each time he went to church. He would sit up the back with his sunglasses on and tissues in his pockets “so that no one would see the tears rolling from my eyes.” A young man at the church took Varicak under his wing and led him to a place where he could accept God; two weeks later he was baptised in the pool at the house of some local missionaries.

“It was such an joyous time. I could serve 100 per cent when the Lord was in that.”

“In hindsight, I see that part of God’s plan for me was to see how missionaries were. The joy bubbles up to see he had my life in his hands and his plan for my life was coming to fruition,” he says.

It would be nice to say that after giving his life to the Lord, Varicak’s path went smoothly. But after returning to Geelong he started drinking heavily again with his old mates, and had two motorbike accidents that landed him in three months of rehab.

“Then there was that thing again: sell everything you’ve got and go. And I left Geelong and … ended up in Mackay a month and a half later.”

It was while working as a volunteer truck driver for the Salvation Army in Mackay that Varicak found the thing he was called to do.

“It was the first time I did something for people in general without any recognition, without any pay. It was such an joyous time. I could serve 100 per cent when the Lord was in that,” he says.

Rob and Tianne prepare to fly to the Didinga hills in South Sudan. Rob Varicak

At the end of 2005 he did a Certificate IV in Christian ministry and a Certificate II in community services, then spent two months serving overseas in Africa. “And it was in Africa, in Malawi, that I gave my life to the Lord in cross-cultural service. I said, ‘Lord, if this is what you have called me to do, then I’m here.’”

Back in Australia, he spent three and a half years training in theology at the North Queensland College of Ministry then worked in Muslim ministry in Townsville and Geelong before an opportunity opened up with ministry to refugees from South Sudan.

“A year later, at the end of 2013, I ended up in South Sudan building houses and doing mechanical maintenance for missionaries. We needed to learn language but the schools were closed in Northern Sudan because of war so they sent us to Egypt.”

 I said, ‘Lord, if this is what you have called me to do, then I’m here.’”

It was in Egypt that Varicak met and fell in love with a tall, beautiful American midwife called Tianne, who shared his passion for serving in South Sudan.

“When I met Rob, I’d just turned 30 and I thought I’m probably going to be single on the mission field,” says Tianne.

“I feel the safest place we can be is in the centre of God’s will.”

“I wasn’t expecting to meet anyone but I met Rob the first week I was in Egypt. He had a heart for the Lord, of course, for mission in South Sudan as I did, so I really connected with him.”

In 2014 Rob and Tianne spent three months together on the same base in South Sudan and it was there Rob asked Tianne to marry him.

Six months later they married in America before returning to Victoria with a plan to return to South Sudan with African Inland Mission in May this year. That plan was postponed to next January when Tianne fell pregnant, with her baby due at the end of this month.

They will be based in the Didinga Hills area, with Rob focusing on building relationships with the young men through different farming techniques and Tianne continuing to serve as a midwife.

“I feel the safest place we can be is in the centre of God’s will. And there’s no guarantee of security wherever we live,” says Tianne.