What is an example of a literary theme?

In contemporary literary studies, a theme is the central topic a text treats. Themes can be divided into two categories: a work's thematic concept is what readers "think the work is about" and its thematic statement being "what the work says about the subject". A story may have several themes.

Hope this helps.

An example could be, 'Slow and steady wins the race', or any moral that relates  to the text.