GRAND PRAIRIE, Texas -- Classes started at Grand Prairie High School this week with heavy hearts, and without Principal Lorimer Arendse.

He is in his fourth year as principal, in his mid 40's and the father of four children. He's a college athlete who never smoked a day in his life.

"I’ve experienced shortness of breath, but I just thought I was getting old," he said.

In June, a fall sent him to the doctor, and x-rays followed. It was then he learned he had Stage 4 lung cancer. Lung cancer rates in non-smokers like Arendse have doubled in a decade. A weakened immune system is keeping him from school. He’ll start chemo treatments at home next week.

"I have an incredible wife," said Arendse of Jeanelle. "She has been by my side. And then my kids...just tremendous."

His strength is in family and faith. "I don’t have a lot of time to spend here on earth, but I do have eternity in heaven," he said.

And that's also comforting to the co-workers who love him.

"It kind of gave me a peace about it," said GPHS Teacher Melanie Hall. "Because I knew he’d have an army back here fighting with him along the way."

That Grand Prairie High army is raising money and writing letters to make sure he knows it. Each note encourages Arendse to use his the rest of his life to teach this final lesson.

"Treat each other with kindness. Be respectful. Be courteous. Be what a Gopher is," he said. "That is the ultimate prize at Grand Prairie High School."

For more on the Arendse family and how you can help, visit their GoFundMe page.