Whenever I meet someone who volunteers for Oxfam, I ask about their motivation. What inspires you to spend your free time tackling issues like climate change or world hunger—issues that can seem distant and insurmountable?

The answers rarely have to do with the issues per se. Instead, they’re about people.

Volunteers talk about how they feel when they hear about the injustices facing poor people worldwide. They tell me about the sense of community they experience when they join with others who share their passion for fighting those injustices. Most of all, they talk about the power of connecting with someone else—a legislator, a fellow student, a neighbor—and getting them to feel that passion too.

“One person is powerful,” said Grace Castro, a college senior from Miami, FL. “If one person is doing something, that’s going to inspire someone else to do something. Never underestimate your efforts.”

It’s the same belief that drives national movements like the MLK Day of Service last week, when hundreds of thousands of Americans spent a holiday Monday performing volunteer work in their communities.

So, in that same spirit, I wanted to share a short video interview (above) with Castro and her fellow University of Miami Oxfam Club member Lissette Miller. I met Castro and Miller in October, when they organized a panel on campus featuring the visiting Haitian farmer and community leader Jacqueline Morette. Both had been involved with Oxfam before: Castro as an Oxfam America CHANGE Leader, and Miller in the Oxfam Action Corps. They told me a little about what their club does, why they volunteer, and why they believe everyone’s efforts matter.

So watch, listen, and maybe feel inspired to do something of your own.