updated 02/21/2012 AT 1:40 PM ET
•originally published 02/22/2012 AT 1:00 PM ET
The actor, 39, founded the Eastern Congo Initiative in 2010 and recently got back from his eighth trip to the war-torn region. Affleck says it’s his kids, Violet, 6 and Seraphina, 3, who inspire him to do good in the world.
“I got to a point in my life where I felt like I had been very fortunate,” Affleck tells PEOPLE in an interview for the Feb. 27 issue, on newsstands now.
“And I wanted to do something more with my life than just make movies and try to make money. I wanted to do something that was important to me in other ways and would serve as an example to my kids.”