A copy of a letter that Jeremiah sent to those who were to be taken to Babylon as exiles by the king of the Babylonians, to give them the message that God had commanded him. 

Because of the sins that you have committed before God, you will be taken to Babylon as exiles by Nebuchadnezzar, king of the Babylonians.  Therefore when you have come to Babylon you will remain there for many years, for a long time, up to seven generations; after that I will bring you away from there in peace.  Now in Babylon you will see gods made of silver and gold and wood, which people carry on their shoulders, and which cause the heathen to fear.  So beware of becoming at all like the foreigners or of letting fear for these gods possess you when you see the multitude before and behind them worshiping them.  But say in your heart, “It is you, O Lord, whom we must worship.”  For my angel is with you, and he is watching over your lives.

Jeremiah wrote this letter to the Israelites heading into captivity at the hands of the Babylonians.  It warns them that while they are there they will encounter many of the Babylonian idols.  They will see a multitude of people before and behind them worshipping these idols, but they must not.  They must pray to God in their hearts; they have a mighty angel to help them.

This same theme is taken up by Jesus and the apostles.  “You are foreigners on the earth, therefore conduct yourselves reverently.”  We, too, are tempted by the many idols we see all around us, for everyone seems to be worshipping them.  It can be very difficult to remember that we are foreigners on this earth.  When we forget we become seduced by the passing allurements of this world and begin making its idols our own.  But we have the Word of God which we must take up daily to worship and to help us.  And we have a mighty angel by our side – shy though they are so that we might not become distracted by our true subject of worship – to help us against the foe.

Addendum

The more of the Sacred Scriptures I read the more I see a micro/macro relationship between everything.  In this case, what is happening to those going into exile relates to that which occurs in the soul desiring God.  The Israelites are being sent to Babylon for punishment for their offenses.  Only our dear God could possibly do such a thing then tell the people: “you will be there for many years; while you are there, be warned – you are not to worship their idols.  It is I you must worship!”  In the same way, for the soul given over to Him we see the purgation of the senses followed later, if he is willing, the passive purgation of the soul, so that any last trace or semblance of attachments in the soul are burned out.  It is as if he tells the soul, like the Israelites: I am turning out the lights on you, so be warned, you might be tempted to set up idols you can sense in the darkness – do not do so!  For I am operating on you; I alone.  Afterwards you will be brought out in peace.  And his ineffable goodness does not leave us alone, but with our most precious guardians.