Mark believes that every person is of value and deserves to be treated with respect.
It's fair to say it's bigger than what I anticipated but in a good way," he says, running a hand through his hair. "It's a challenge. I've had to wrap my head around it reasonably quickly."
He recounts a story from his first week on the job.
"I sat in on one of the programmes. The women had overcome drug and alcohol addiction. They shared their stories. Of those nine women, six of them said they would not be alive today if it were not for the City Mission," Mark says. "That really stuck with me."
It is clear their stories moved him.
"These women are someone's mum or daughter. They felt they had no value. To be able to take them from that place of hopelessness to where they are an important part of our community, there's so much value in that."
When Mark talks about value or worth, he's not counting dollars and cents.
He wants to start a conversation in our community about what we, collectively, are going to do to help those people among us who are struggling. He's talking about our working poor, our homeless, our mentally ill and our substance abusers.
In Christchurch homelessness is rising, agencies are struggling to cope with demand for mental health services and the numbers of people dealing with addiction to methamphetamines and synthetic cannabis is escalating.
Most people would know the mission offers a food bank and a men's night shelter but might not be fully aware of all its services. It also offers a women's shelter, a men's day programme, two women's programmes, an alcohol and drug detox programme and emergency accommodation for families.
If someone goes to the City Mission for a food parcel, help doesn't end there.
"We say 'fine we can meet that immediate need but do you need help with budgeting, do your children need help with schooling through our back to school programme? Is there anything we need to look at around addiction? Or, from a personal perspective, are you ok?'," says Mark.
"It may be we bring in a counsellor or one of our nurses who works with mental health issues. If there's an addiction issue they can do an alcohol and drug detox here and we also do that in the home. There's a raft of services and all are intertwined."
In Christchurch, Mark says, we have meth addicts aged from as young as 14 right through to those at "the very senior end" of their lives.
How bad is it?
"One of the key trends we are seeing is a significant increase in meth and synthetic cannabis use and that is increasing year on year. That's a tough one."
Mark pauses, his hand makes a small fist on his desk: "It's a scourge on our society, it really is."
He sighs and glances out the window.
"Our mental health service is completely slammed."
"I know we are talking six years ago since the earthquakes, there is still flow on from there. It's no slight on the medical fraternity, the demand is so huge we are not able to meet that adequately."
He says mental health issues pose the biggest challenge.
"There is a significant increase in those we are serving who have mental health issues. it leads to a plethora of other issues when that is not managed well."
There's no magic solution to our region's rising mental health problems.
"Is it a government problem? A CDHB problem? A community problem? Or do we all work together to make our community stronger? This is a conversation we need to have. It's difficult for many people but we need to talk about it."
Homelessness in Christchurch? It's worse than you think.
"The homelessness has been an eye opener for me. I don't think we truly realise in Christchurch how large this problem is. It's hard to put a number on it, because you can't – so many people hide it. They might be living in a car, shed, sleeping rough or couch surfing on people's couches. Their stories are heartbreaking."
The largest increase in those who are sleeping rough in the last 18 months? Our young people and our women: "It's safer for them to be living rough than in their home environment."
Homelessness, mental health, drug and alcohol addiction – these problems are often intertwined.
Mark believes that every person is of value and deserves to be treated with respect.
Outside the rain stops and a reflection from the window makes a rainbow on his face as he says: "No one of us is better than the other."
The slide into poverty and homelessness can happen uncomfortably quickly, with just one "slightly off course choice".
People have been numbed to such problems to an extent. There's a wariness in our attitudes towards our less fortunate, particularly when someone has made a poor choice.
"We need to change people's perceptions around that for people to understand that there are people who are less fortunate but it doesn't make them any less valued. Irrespective of how they got to where they are, there is a need. How do we meet that need and cause that not to happen again?"
However, Mark does admit that such wariness is sometimes justified.
"I need to make a distinction between homelessness and those for whom begging is a business," he says. "Buy someone some food or take them to an agency like the City Mission."
There's a saying at the City Mission that I'm sure I'd find above a doorway somewhere if I looked: "It's not a handout, it's a hand up".
Mark says there has also been a "significant increase in the working poor" seeking help.
"We are seeing more and more working families, mum and dad are working, particularly with a young family. They might be on a low income and can't make ends meet. They are the ones coming to our food bank. More often than not, they are minimum wage, low wage. Rent over the years has increased, pay hasn't kept pace with that."
Sadly, Mark says their "greatest growth area" is children in need of books or a school uniform.
"It's indicative of that working poor. We have seen that increase almost threefold in the last 18 months... That's where the working wage becomes an important discussion. How do we get people into that income space where they can keep their heads above water?"
Mark has a gentle manner and readily shows kindness. He smiles often and talks in positive buzzwords.
But he's capable of being tough when he has to.
Take, for example, his stance on the rise in "truck shops" – mobile shops selling goods to the vulnerable on finance.
"We have them turn up here and I'm out there quicker than Flash Gordon. They're not welcome. They prowl and prey on the unsuspecting, those who don't have the means to understand what they are getting themselves into. It's a dangerous space."
The City Mission works with other agencies in the city to help those who really need it. But Mark thinks we can all do our bit.
"A lot of it is about self worth," he says. "If you see a homeless person on the street with their head down, it could be as simple as engaging them in a conversation or just saying 'hi'. You see their head rise up again and it's a remarkable thing. Look up from your screen and see what is really going on."
Does being surrounded by troubled people ever take its toll?
"I love people. My goal is always 'how can I enhance someone?' In those tough times, the thinking is not about me."
There's a religious aspect but the big fella upstairs only comes up once, briefly, in our hour long conversation.
Ronald McDonald House changed Mark's life. He'll never forget his time there. We speak on the anniversary of the death of Jayden Morris, a Southland boy who was just 11 years old when he died from a primitive neuroectodermal tumour (PNET) - a brain tumour - last year. Mark has been thinking about it on and off all day.
"He was an amazing young man, just a beautiful young man," says Mark.
Why does he think he's drawn to caring professions?
An awkward expression briefly crosses his face.
"Golly," he exclaims.
It's the first time I've heard anyone outside of an Enid Blyton book use the word.
"Golly," he repeats. "I think it's ingrained... it's just part of the nature of who I am."
He has four children, three sons and a daughter in their early 20s. His youngest boy, Jeremy, is 17. His wife, Sheila, is a pastoral care worker "involved in community space". His face looks like a lighthouse when he talks about them.
Six weeks in to life at the City Mission, Mark is positive that he can help make a difference.
"Our brown bag appeal is coming up in June," he says. "The tagline is 'Real people, real need' and that is who we are serving."