Northrop Frye
The Great Code (1982)
The verbal culture of a prediscursive society will consist largely
of stories, but among those stories there grows up a
specialization in social function that affects some stories more
than others. Certain stories seem to have a peculiar significance:
they are the stories that tell a society what is important for it to
know, whether about its gods, its history, its laws, or its class
structure. These stories may be called myths in a secondary
sense, a sense that distinguishes them from folktales - stories told
for entertainment or other less central purposes. They thus
become “sacred” as distinct from “profane” stories, and form
part of what the Biblical tradition calls revelation. ... Mythical, in
this secondary sense, therefore means the opposite of  “not really
true”: it means being charged with a special seriousness and
importance.