I think that nowadays there are a lot of problems in the world, but the main is that the mayority of people don't care about them. Surely, if everyone worked and took part in the rebuilding of a better world, it would be much easier to achieve it.
After making people aware, we all need to work hard with the purpose of ending with the poverty, hunger and injustice. For that, it isn't enough to give money or clothes to poor people, it's also important that we ourselves work to defend and respect each other.
We don't need to work thinking about very big objectives, we have to start the change in our daily acts. It would be better the help you give a person with problems in your school or work place than trying to help people in Africa who you don't know.