The story of Baucis and Philemon is a great one. Here are the details, which we can read about in the Roman poet Ovid. Baucis and Philemon are an old couple that live in Phrygia. Jupiter and Mercury come to their town disguised as common peasants looking for lodging. The whole town rejected them and did not show hospitality, except for a poor old couple, Baucis and Philemon. They invited Jupiter and Mercury into their home and fed them wine. After some time, Baucis realized that the wine did not run out. So, she concluded that these guests were gods. She was right.
For the impiety or the lack of hospitality of the town, the gods destroyed the town, except for the home of Baucis and Philemon. Their home actually became a temple. The gods also gave a wish to Baucis and Philemon. They used their wish to ask for the privilege to be guardians of the temple and die with each other, so that they would never be apart. When they died, the gods turned them into two intertwined trees next to the temple.
It is a great story, as you can see. One theme is the importance of hospitality. Breeches of this could cause the anger of the gods!