The notion behind a typical service project or service-learning class is that acts of service, civic engagement, or activism take a flawed reality (homelessness, poverty, hunger, discrimination, etc.) and tries to move it towards an ideal (justice, equity, access, peace, etc.).
But consider these lines, from Shinso Ito, a master in the Shinnyo-en branch of Japanese Buddhism:
By channeling your energy into acts of service, you transform the ideal into the real.
Here, Ito is arguing that the "ideal" is that thing floating in our heads--some notion about how things are, or should be. But since all is impermanence in Buddhism, that ideal in our heads is really getting in the way of our ability to perceive things as they are. Service, he suggests, can strip away the falseness, both because it gets us out of the conversations running in our heads (in the way that meditation aims to do) and because it introduces us physically to a reality that does not get experienced otherwise.
So what are civic engagement practitioners to learn from Ito's argument? To be humble in the face of reality. To trust that when service leads someone to say they have been changed in ways they cannot describe, they are telling the truth, not being superficial. And to be skeptical of efforts to respond to abstract problems in abstract ways. "Service" does not help "homelessness." But people can work together in ways that helps them see the world real, and as they remake that world, remake themselves as well.