It's the Bible verse that has inspired Jarryd Hayne's gigantic leap of faith from the harbour city to the Golden Gate.

San Francisco, a city often blinded by thick fog and renowned for its steep roads, is the scene of Hayne's very own mission.

Just less than an hour south of the picturesque bayside metropolis, in a hotel room in Santa Clara close to the new San Francisco 49ers' home, Levi's Stadium, Hayne is still trying to see through that fog.

And it's anything but sunny days ahead for the faith-guided 27-year-old from western Sydney.

There are those who crumble at the thought of leaving their comfort zone. But Hayne, described by many as somewhat unorthodox in his approach to life, was struggling in the glory of his own success in Australia.

Suddenly, being the best was no longer enough.

Some describe his move to try to break into the NFL as stupidity. Others called it naivety. It might have been both.

Others said it was brave, even courageous. But no amount of self belief would prepare him for what he would have to endure throughout a six-month journey of self discovery between walking out on his beloved Eels and landing at the front door of the 49ers earlier this month.

"Honestly, if I had been told the things that I went through before this journey started, I honestly think I wouldn't have done it," Hayne told Fairfax Media at Levi's Stadium this week after he was unveiled to the US media.

"There have been so many things that have just pushed and pulled at me and really broke me down physically and mentally. But spiritually, it's the one thing that got me through.

"That's why when I read Bible verses I just understand them. It's one thing reading Bible verses but it's another thing living it.  A man plans his course but God determines his steps. That couldn't be more true."

Had he remained at Parramatta, it's safe to assume that he would have become the highest-paid player in the game when his contract was originally meant to expire at the end of this year.

Hayne first revealed his desire to challenge himself outside  the NRL in a candid interview during last year's State of Origin series. It was clear, from the way he spoke about the culture of sport in the US, that he would feel more at home away from home.

Reality can be harsh

But the vision he might have had in his head of what it would be like is anything like the reality he's living at the moment.

He's renting a car, sharing a room with a 49ers teammate and living off less than the NRL minimum wage. But this isn't about the money. It never was.

"I left Australia with no plan and left everything behind," Hayne said.

"I left behind a multimillion-dollar deal to come over, and we still don't get paid until week one of the season. I'm earning $600 a week until the start of the season (September). I'm getting paid less than an apprenticeship back home. I stopped getting paid in September last year. But this was never about the money. I know what I'm over here for. If I lose everything, then so be it. As a person, you want to challenge yourself. When I got the green light to come here, it triggered something inside of me. I said to myself 'bro, it doesn't matter what happens, it doesn't matter what I go through, just keep pushing'. That's been my mentality the whole time and it's got me this far.

"When you're chasing a dream, money goes out the window. It really does. At the end of the day I want to be remembered by others and remember myself for the experiences you go through in life. This whole opportunity to come to San Fran and play for such a great organisation and learning a new sport, that's what drives me. Money doesn't matter. If I lose money, so be it. I want to live a life that isn't the life of regrets. I want to live a life that's adventurous, that's challenging. When I set a goal, I set out to do it no matter how hard it gets."

And it did get hard. Despite interest from US agents he spent two months travelling in the US trying to make a noise in a country that usually only listens to the voices of its own.

And even though he has achieved more than most expected he would accomplish in a foreign market, the uncertainty of the road ahead took its toll.

"Sometimes I'd be sitting there on my own swearing at myself saying 'what the f--- am I doing here, this is ridiculous, I'm busting my balls, why can't shit be smooth?" Hayne said. "But that's one of the things I have to do, live and learn. The people close to me know how strong my mentality is, how strong I am as a person to persevere through those situations. When I go through those things, as long as I keep telling myself 'it's just a learning curve, it's just a learning curve, you'll be better for the long run'. January and February were tough. I didn't know what I was going to do. I thought I was going to be somewhere and then things weren't happening.

"I had a couple of things back home and my head was everywhere. I wasn't really focusing and mentally I wasn't with it at times. Now I know where I am and what I'm doing, I have that sense of purpose again. Not knowing where I was going or what team I was going to, that really strained me and stressed me out given what I'd done to put myself in that position. For me, I feel I handled it really well. When you look back you always think you could have done things better or you realise that the things you were worrying about were never worth worrying about in the first place. It was definitely a learning curve."

Learning the playbook

His teammates have been impressed and all reports coming out of the US suggest he is more than holding his own in the early speed and strength testing. But his true test is still to come.

"At Parra a few boys struggled remembering a couple of plays in a set," he laughs as he rocks back on the chair inside one of the 49ers' offices. "The playbook ... man."

Yep, that playbook. It's the obstacle of monumental proportions that is challenging Hayne. "Just watching video of me training, you can tell when I don't know what I'm doing because I step a lot more and waste a lot of energy being very nervous," he said.

"Those are the little things I'm picking up on and the coach has said make those mistakes now because you don't want to be making those mistakes when we come back in July. I'm still finding my feet. When I feel comfortable and in a rhythm, I'm not really in a rhythm at the moment so I'm still chasing my tail from a perspective of learning the playbook. That's what's been tough. That's the killer."

The spotlight is no longer on him the way it was in Australia, and while he's as unrecognisable in the city as the Aussie slang he uses in the locker room, there are the diehard 49ers fans who acknowledge his presence in the Bay area. "I got screamed at as the Hayne train the other day," he says.

"This bloke was beeping his horn and I was like 'is he waving at me?'. 'I don't know anyone in America, what's going on'. Some San Fran fans are really supportive and backing me to succeed for the team. To be honest even back home the support has been overwhelming. I was getting tweets from fans saying 'I used to hate you as a player when you played for Parra or NSW but I'm so proud and happy for what you're doing and we're supporting you'.

"Those little messages I smile at. I don't really take any consideration from the fact they used to hate me, but the fact they see what I'm doing for what it is, that I'm over here doing my best and having a crack, that's all I could ask."

For some, the dream would be complete.

For Hayne, this pilgrimage ends with helmet in hand walking out of the tunnel to the blinding lights of the NFL.