Bono

I know that just about everyone has either heard or read Bono's sermon at the Prayer Breakfast. It was fabulous and I am still pondering things from it.
What is the difference between chairty and justice? I have glimpses of an answer to that question but there is so much still to uncover. I guess what makes me uncomfortable is the fact that my life has been more about charity than justice, yet I have previously thought of myself as a champion of justice.
It seems to me that Charity is giving from a place of "having" to a people who "have not" without affecting change for their long-term hope and living. Justice is sharing so that we all have enough even though "enough" is different in Africa and America. That justice sets into motion the potential for a life of hope, chance, opportunity and viability. Justice longs for the life of people to be transformed into something and charity focuses on the act of my giving without really connecting me to the pain of a people.
How do I teach this to my children? How do I learn how to live in such a way that I fight for the rights of the marginal?
Jesus was about justice.