This is a wonderful chapter. God's people have abandoned Him and served other gods, over and over again, and as a result they are about to be taken into exile to Babylon. There is no doubt in the text that this is punishment for their unfaithfulness, and a fulfillment of the Curse which Moses warned them of, should they abandon their Lord and Saviour.
Yet, love and gentleness are evident here. In Jeremiah 27, God has told His people that if they submit to this inevitable exile graciously and humbly, and do not resist the Babylonians, that they will be spared the murderous destruction that was typical of conquest at that time, and their lives will be spared. But the false prophets argue and subvert Jeremiah's admonition by telling the people that Babylon will fall in two years (it does not.) The people do resist, and we know that their city fell in fire, rape, pillage, and the dashing of infants' heads against the rocks. This was not what God wanted.
In this chapter, Jeremiah addresses the exiles who were taken in the first wave, before the total destruction. Daniel was among these. They are told to embrace life there in exile, not to pine and despair, but to live, to marry, to have babies, to grow food, and to increase in number (very similar to the command to Adam and Eve to "be fruitful and multiply and fill the earth.") Most surprisingly, rather than try to undermine or sabotage the Babylonian culture, they are to pray for it, to seek its good, to seek the good of any Babylonian city to which they are taken, for "in its prosperity shall be your prosperity." Why? "Because I know my plans for you, plans not for calamity but for a future and a hope." (My wife's favorite verse.) This whole terrible experience is part of God's plan for their good, for their cleansing, even as a loving father sadly chastises his son or daughter so that they will grow up straight and good and have a good life.
We know that God did ultimately judge Babylon for its great pride and brutality, but that was not to be the goal of his people. They were to seek the real good of these pagan cities, and in so doing, could still have a good life even in the midst of their punishment. Many, even most of the exiles would never see Jerusalem again...seventy years was longer than the normal life span. Yet their children would, and these exiles were to make sure that there would be children to return, and that those children understood why they had been exiled, that they would never fall into idolatry again.
As we find ourselves disciplined by the Lord, we should remember Babylon. Though He chastise us, it is because He loves us and seeks our real prosperity. Furthermore, as we live in these pagan cities of the West, knowing that they are not our homes, we should nevertheless live fully in them, seek their prosperity, for in their prosperity will be our prosperity.