That's an old countercultural slogan from the 1960s in America. It means: Never give up. Believe in the good. Here is a little phrase I have on my refrigerator door. (Americans often put photos or magnets with phrases on their metal refrigerator doors, because they see them every day that way -- like a household bulletin board.)
WHAT IS COURAGE?
C = confronting the dragons O = overcoming the obstacles U = understanding the risks R = really living (I love that one especially.) A = always believing G = going the distance (to persist with dedication and intention) E = experiencing the best
To live requires courage. And to live well - for ourselves and others - requires courage and love.