They didn't have to.
They had an elite literate class, first in Jewish times then in
Christian times, who did the readin' and writin' and stuff.
This is the 10th century BC. Lots of stuff going on around the
world at the time.
Think about it; How do we know their names?
How do we know their stories?
[1]
https://en.wikipedia.org/wiki/10th_century_BC
The literate were literate.
The literate taught the illiterate.
People who write poetry use allegory and metaphor.
It's not rocket science.
I don't care of you don't like religion; I think a lot of it is
stupid myself. But replacing one stupid with another stupid just
looks stupid.
References
Visible links
1.
https://en.wikipedia.org/wiki/10th_century_BC