Jeremiah's lament is a reminder that Christians don't have to be relentlessly cheerful. He looks around for good news and can't find any. The harvest is over, but it has not been a good one. The people are hurting, but there is no one to heal them. They have made mistakes, and their errors are coming back to haunt them, a bit like the managers and directors of Northern Rock who gambled on an endless supply of cheap money and were caught out when times suddenly changed.
Unlike the people who have queued up not just to withdraw their deposits, but to point the finger of blame, Jeremiah chooses not to accuse anyone or rub salt in open wounds. He gets alongside the people in their suffering and mourns with them.
But, of course, it's not just Jeremiah who laments with those who have been bereaved, and mourns those who have died. For Jeremiah is reporting God's view point on disaster. Even when we are responsible for our own downfall, God chooses not to blame us but to share our pain. And the final proof of this is Jesus' death for us on the Cross.