Now, a decade on, Walker is living "everything" he was shown "and more".
Walker doesn't shy away from his beliefs, but he doesn't push them on anybody else.
"It is who I am; I am alive because God saved my life because Jesus is alive and it's not like a thing that I've just come to believe in, it's an experience that I have that nobody, not one person can take away from me... I was saved from my own self".
Since then, the 28-year-old has not had an easy road but he wouldn't change it for a life without God.
"I heard this saying one time I was at church and this pastor was like 'I wouldn't have chosen the things that have happened to me, but I wouldn't change it because I am who I am because of everything'.
"I'm like 'ooh that's a bit of a hard pill to swallow' because there are so many things I would change but then I look at my life and I look at where I'm at and I'm like 'no I wouldn't change anything' because it created the little beast I am today," he says with a giggle.
It will be two years this month since Walker was diagnosed with cancer, after 13 spots were found in his stomach, and had the organ removed.
His family's genes include an aggressive CDH1 hereditary mutation, which gave him around 80 per cent chance of getting stomach cancer.
The mutation was responsible for his mother's breast cancer and reportedly for the deaths of at least 25 of his family members.
For his family, they always thought of the mutation as a "curse", but it "just came down to genetics".
"Back in the day people were just dying and there was no cure and there was no way of stopping it but now I know it's not simple but it's as simple as getting your gut out, he says with a little chuckle.
Walker says he "didn't realise it was actually going to happen".
"It just kind of all happened so suddenly. I was surprised, but it wasn't a discouraging thing for me. I don't know I just went to a place real quick where I was like okay I'm going to go through this."
His decision to document his journey was made with relative ease, and as a way to help others in a similar situation.
"I wanted people to see the process from start to finish because you always hear about people's journey's about being sick, especially with cancer and the outcome is always life or death, but nobody sees the process, nobody sees the families involved, nobody sees the science behind it."
Overcoming the battle has changed Walker in ever sense of the word.
He says he's "more ruthless in every area" of his life. "I'm not going to be held back by nothing or nobody.
"It's so amazing because it was like being reborn and just coming into a whole new light and a whole new space, with a new fire."
"When that happened, everybody around me changed too, for the better and we all grew together."
Following a three-year break from recording, Walker released a six-track EP in March 2018 and a four-track EP titled Faith Hope Love earlier this year.
Walker returned to touring last year and is embarking on his "springboard" tour, with up-and-coming new artists – Lepani, Niko Walters and Jordan Gavet.
Joining Walker on stage will be his longstanding backing band The Levites. Consisting of the Nansen brothers, brothers – Jakes (keys), Ross (drums), Junior (bass) and Inoke Finau on guitar.
"Being on stage with my fans and being able to see their lives change right in front of me and hearing their stories of how I've changed their lives and my music is worth it," Walker says.
"I feel like a lion when I'm on stage like I feel like I'm roaring constantly but it's such a liberating feeling. I dunno, it's like ecstasy. I think that's the only way I can explain it, it's just amazing."
If he could give any bit advice to his 18-year-old self, Walker says: "be slow to speak, quick to listen and slow to get angry".
"To relax. Don't be a know it all and just to always have an open heart".
Stan Walker will perform at the Napier Municipal Theatre on Monday, September 16.
