As Jerusalem lay under siege by the Babylonians, the Lord speaks to the prophet Jeremiah. God’s word to Jeremiah, not necessarily in this order, is: Jerusalem will fall to the Babylonians; you will go into exile; this event might be the best thing that ever happened to you; I will bring you back to Jerusalem; and I will establish a new covenant with you.
It is a wonderful word of hope, but it is happening in the midst of tragedy and destruction. The Lord is saying, “I am with you,” but it looks as if he has abandoned his people. However, it is the people who have abandoned the Lord. He compares their relationship to a husband who remains faithful to his wife in spite of her unfaithfulness (Jer. 31:32)—a prevalent theme in the Old Testament.
Those who are carried off to Babylon have been given the assurance they will return, but it is going to be awhile. There will be another “wilderness” period for the Israelites, who will be forced to reckon with themselves and reconcile with God. Why are these times necessary? Sometimes God will go to great lengths in order to pursue a relationship with his people—even if it means making them uncomfortable, for that produces a dependence upon the Lord.
Why was the Israelites’ wandering in the wilderness of Sinai so long? Why will they spend another forty years away from home? Sometimes it takes that long, even successive generations, to be brought to a place where the memory of unfaithfulness is distant.
God’s promise to his people is to make a new covenant with them. This covenant will
“not be like the covenant that I made with their fathers on the day when I took them by the hand to bring them out of the land of Egypt, my covenant that they broke, though I was their husband, declares the Lord. For this is the covenant that I will make with the house of Israel after those days, declares the Lord: I will put my law within them, and I will write it on their hearts. And I will be their God, and they shall be my people. And no longer shall each one teach his neighbor and each his brother, saying, ‘Know the Lord,’ for they shall all know me, from the least of them to the greatest, declares the Lord. For I will forgive their iniquity, and I will remember their sin no more.” (Jer. 31:32-34)
This radical promise of grace and mercy is held out to all. Even the sins whose burden is intolerable shall be forgiven and God will remember them no more. This is a word of hope in the midst of destruction and comfort in exile. Even when you have lost everything, you are able to cling to the Lord Jesus, for he is your all.
 It should be noted that not all of the inhabitants of Judah were carried off. And, their return to Judah was not a one-time event, but gradual.