Just after the Beatitudes, where Jesus turns the normal, run-of-the-mill, follow-all-these-rules-and-you’ll-be-saved idea on its head, he shocks the listeners with this metaphor:
“You are the salt of the earth.” Matthew 5:13.
Salt was vital and life-giving in the ancient world. It was used for healing, cleansing wounds and preserving. Covenants entered were called “salt covenants,” agreements that...