Keith Holder and his wife Joy have been working with children in Costa Rica for the last 20 years.
Originally from Essex, he set up Educación Plus, an organisation running Bible clubs, sports and educational activities for around 500 children.
As a trained pastor, it's important to Keith that their work doesn't just give the children practical life skills, but also the spiritual truths they need to flourish.
"It's an interesting life and there's rarely a dull moment. It's not just about us overseeing 500 kids, it's about inputting truth into them so they are prepared for life," he says. "It's a practical outworking of the gospel," he adds.
Many of the children are from impoverished families and substance abuse is a real issue.
"Some of the boys who sniff glue have been in our Bible classes. We care for them and love them and show them the good news. Without being super spiritual, we believe we are God's presence in the shanty town," he explains.
That's why Keith and Joy also reach out to the parents and the wider community.
"Some of the kids I work with are in their teens but I started getting to know their families when they were just ten. We build relationship and liaise with their parents and schools. We get involved with the whole community and the idea is to keep the kids off the streets and out of trouble.
"We also don't just focus on the children but we try and help the parents. For many of them, all they've ever known is poverty so it's about breaking the cycle. I don't want to see them hooked on sniffing glue or taking marijuana so I'm motivated to make a difference."
Keith's hard work over the years was recognised with an MBE from the Queen in 2011, but he is keen to stress he wasn't looking for recognition.
"We went to Buckingham Palace to get the award and I was a bit embarrassed really because although people congratulate us for the work we've done in Costa Rica, we've always just felt that all we are doing is obeying God.
"There have been sacrifices along the way but when you do something so enjoyable you don't expect an award for it."
And he may have had some scary experiences in Costa Rica, but even they didn't compare to meeting the Queen.
"It was a nerve-wracking experience, meeting the Queen, even more so than when we were breaking up a knife fight in the shanty towns of Costa Rica. There have been other scary experiences we've been through too," he says.
Although he is modest about what he has sacrificed over the years, he admits that one of the hardest things is being so far away from his own children.
"As Christians, we're supposed to be good news wherever we go. It's not always easy being a missionary. We have three children of our own back home and we don't get to see them much and that's the hardest part, but we know God's called us to do this and it's a great privilege."
Keith and Joy are supported by Rope, a Christian development charity based in Buckinghamshire. Rope helps provide shoes and clothing for children who don't fall under the Educación Plus remit while they also give help to parents with food and medical bills.
Rope's Chief Executive Jon Dobbs said: "Keith and Joy are an inspiration to us all. Working in these circumstances is not everyone's call, but they are clearly gifted and called to the young people and families in Costa Rica. It's hard work but so rewarding when God transforms lives. Rope considers it a privilege to partner with them in this work."