When I was young, even when I was older, I yearned to know how God was to use me to help save the world. COuld I work for Amnesty International? COuld I work for Oxfam, or some fair trade organization? What about Greenpeace.
Then I became a foster parent. Not too much different from any other parent except you have to fight for economic justice as hard as any NGO in existence.
You have to consistently convince governments that children's rights include gender equality, a just economic system, non-violence and mental health rights.
So, if you find yourself flustering about where God wants you to help do not rule foster care out.