A great and tragic lament arose from the hearts and lips of God's chosen people when they were exiled to Babylon. It was not only a matter of the hardships of physical expatriation, nor of the social and cultural humiliation experienced at the hands of their enemies. Their greatest sorrow was having to be banished from the Temple of the Lord and his holy city, along with the knowledge that it had been razed to the ground.
The Temple was the dwelling place of the Lord and hence the only place where sacrifice and true worship could be offered. How could they now expiate their sins? Psalms composed (in whole or in part) during the time of exile expressed the need to find some way to connect with God, to somehow substitute for the Temple worship. "Let my prayer rise like incense before You"--for incense could no longer be offered in the Temple-- "the lifting of my hands like the evening sacrifice"--for there were no more sacrifices in the Temple (Psalm 140/141). For the same reason: "My sacrifice is a broken spirit, a humble and contrite heart..." (Psalm 50/51).
But nothing could ever really take the place of Jerusalem and the Temple. Hence we have the deeply poignant Psalm 136/137: "By the rivers of Babylon we sat and wept, remembering Zion... Our captors asked of us, 'Sing for us the songs of Zion!' How could we sing the song of the Lord in a foreign land? If I forget you, Jerusalem, let my right hand wither... Let my tongue cleave to my mouth...if I consider not Jerusalem the source of my joy."
We too are in exile. We have been banished from Paradise because of our sins. But for many it may seem such an ancient and distant memory that they no longer lament its loss (or perhaps they have simply resigned themselves to lives of quiet desperation). But Christians still long for Jerusalem, that is, the New Jerusalem, Heaven, of which all believers are citizens (see Philippians 3:20). If we have lost our awareness of being exiles from Paradise, citizens of Heaven, and have thus contented ourselves with life in Babylon, we must at once recover our longing. We must not forget Heaven, for such forgetfulness puts us on the path to sin. To sin is to forget that Heaven is the source of our joy. If we do forget "Jerusalem," we end up looking to other, foreign, polluted sources that can never provide true or lasting happiness. Heaven is where we belong, for Heaven we were created, for Heaven God has destined us--if only we choose to leave Babylon (in spirit, for we cannot yet leave the earth) and return to our fatherland.
We are in exile, but not without hope. We are in a foreign land, but not without a passport. We have fallen from grace, but we can be restored. We may still have many years to live far from Paradise, but earthly exile is not forever. Forget not Jerusalem, and the Lord will bring you home.