I’m stymied by the story in Genesis where Lot’s wife turns into a pillar of salt. Can you please explain it to me?
The inhabitants of Sodom were known for their cruelty to strangers. In fact, inhospitality was included in their code of law.
Lot was the exception. Although he lived in Sodom, the years that he had spent with his uncle Abraham had influenced him, and he had learned to emulate Abraham's hospitality.
When G‑d sent two angels, disguised as men, to destroy Sodom, Lot invited them to his home and served them food. His wife Adit, a native Sodomite, disapproved of his actions.
Lot asked his wife for salt for the guests and she replied, "Also this evil custom you wish to introduce into this place?” She had no salt in the house and went from door to door asking neighbors for salt for her husband's guests, letting everyone know that Lot had ignored the laws of the city by inviting strangers. A short time later, a mob gathered at Lot's door, demanding that he give up his guests to be mistreated.
The next morning, as Sodom was about to be destroyed, the angels rescued Lot and his family. As they fled, the angels warned them not to look back at the city. It was not appropriate for them to stare at the suffering of others. But Lot's wife disregarded the admonition and, "She looked from behind, and she became a pillar of salt (Genesis 19:26)."
The Midrash explains, "She sinned with salt, and she was punished with salt."
For more information see our articles on the Destruction of Sodom & Gomorrah.