In why is this statement considered a them and not a plot summary true friends will always be there for you when you need them

This statement could be considered a theme becuase

A theme is what the work under consideration tells you about life beyond the work itself while a summary tells the reader the main action of the work without the reader having to read through the entire work in order to know more about it.

in paragraph 6 of "sinners in the hands of an angry god" by jonathan edwards, he talks about how doing good things alone will not save men from going to hell because they're at the mercy of the will of god. "spiritual reform" provides men with a false sense of safety.