Principle: Seek the welfare of the city.
Historical example: I am currently reading through the book of Jeremiah. In chapter 29 Jeremiah is once again revealed to be a true prophet of God amidst a culture replete with false prophets. Jeremiah is telling the people of Judah who are being exiled to Babylon (present-day Iraq) that, even when they are exiles, they are to seek the welfare of the city. That is, regardless of how bad one’s culture is, God’s people are to seek to do good to all men.
“But seek the welfare of the city where I have sent you into exile, and pray to the LORD on its behalf, for in its welfare you will find your welfare” (Jer 29:7 ESV).
We find the same principle of doing good unto all repeated in the NT: “So then, as we have opportunity, let us do good to everyone, and especially to those who are of the household of faith” (Gal 6:10 ESV).
Folksy wisdom might express this principle this way: Bloom where you are planted. This is easy to quote but hard to live. We all tend to think the grass is greener just over that next hill. But sometimes just over that next hill is a septic tank.
Encouragement: Where God has us, let us seek the welfare of the city. That is, let us better our environs rather than desecrate them. How can we do that? By seeking the welfare of whatever city God has us in.