A didactic story teaches the reader a lesson.
"The Three Little Pigs is a didactic story."
...It teaches the reader to prepare for the future by working hard.
Said as: dy-dak-tik
Didactic means used for teaching
1. Intended to instruct.
2. Morally instructive.
3. Inclined to teach or moralize excessively.
Didactic plays, for instance, teach the audience through the use of a moral or a theme.