Theory offers an abstract overview of an entire situation. Theory evolves from a study of specific instances of the subject under consideration. It is like looking at a map of the entire planet, rather than focusing on one particular home. It may not be true in every single instance, but it gives us guidelines and structures for understanding the specifics and making decisions that will benefit us all. It is likely true most of the time.
It is useful to move back and forth from theory to stories to quotations to examples to practices. Each gives a different perspective on the same topic.