NOVATO, Calif. (KGO) -- Life for Chris and Brittany Kurtz changed drastically about a year ago.
That's when Chris included four little words in his email signature. They said, "Do Good. Be Kind."
Brittany made him a t-shirt with the expression, snapped a picture and put it on Instagram. And then it started happening.
RELATED: Woman's act of kindness toward stranger goes viral
"That day we had so many people saying, where do I get that shirt. That's such a great saying. The world needs more of that right now," said Brittany Kurtz, who then started making shirts for people who requested one.
But the requests grew so large that she and her husband eventually set up a website to sell shirts, hoodies, caps and other merchandise. All of it with those same four words.
"A lot of people buy it thinking that it is going to be a good message to send out. For them to wear. What I don't think they anticipate is how it changes them internally," said Chris Kurtz.
The Novato couple says they get messages daily from people telling them how they are nicer and more courteous while they are wearing the shirt, so they don't betray the "Do Good. Be Kind." expression that they are wearing.
RELATED: Choose Kindness - The Bay Area is no place for bullies
The movement took another leap when the principal at Rancho Elementary School saw a teacher wearing one of the shirts.
She asked the Kurtz family to bring their kindness message to her school, so they created a week-long program for students.
"Instead of anti-bullying, we switched the script and focus on being proactive. Doing something good can be as simple as making your bed in the morning. Being kind to the world around you can be cleaning up your room," explained Chris Kurtz while preparing for a student assembly at Lu Sutton Elementary School in Novato.
At the end of the week, the students get a "Do Good. Be Kind." shirt to wear as a reminder to continue acting on the principles and values that those four words represent.
Click here for more stories related to acts of kindness.