If you take the burden of health care, of diseases off the backs of some other countries, it gives them a chance to use their own very limited resources in ways that help their people. And also there's a hopelessness associated with deadly diseases, that if that can be alleviated, people can build their own economies in their own countries and they'll be less reliant on the developed world for help.
Giving homeless children the chance to be educated, giving them this ticket to their futures, is so wonderful. They will have the chance to not repeat the suffering of their childhoods in their own families. They can build secure and safe lives for themselves and their children.
Reading will give you lasting pleasure.