Why the words of Isaiah never get old

The Book of Isaiah is incredibly versatile.  We read from it regularly at Mass.  Its words speak strongly to us year of year when we are passing through very different circumstances.  The rich versatility of Isaiah arises in part from the fact that although it possesses an overall unity, different voices are discernible which were initially aimed at distinct audiences in dissimilar settings at specific moments in history.  When we identify with certain aspects of one of these audiences, the message originally intended for them exerts power over us.
Chapters 1-39 of Isaiah were initially directed towards a people under threat in the 2nd half of the 8th century BC.  At this time, both the kingdoms of Israel and Judah faced the very real possibility of being wiped of the map by the Assyrians, the strongest and most brutal force at that time.  Isaiah called this threatened people to trust in God and to use this moment of crisis to convert and grow closer to Him.  At different times, we too can feel as though everything is about to be taken away from us.  Those faced with health troubles, financial insecurities or tensions in their marriage often feel like they are living under the weight of a looming threat.
Chapters 40-48 were originally spoken to a devastated people in the 2nd half of the 6th century BC.  At this time, the Jews were living in exile in Babylon.  The temple, Jerusalem and the surrounding cities lay in ruins.  All seemed lost and many felt abandoned by God.  To this people, the author of Isaiah spoke a message of hope in the darkness: God is still with you and He will make something new rise from the ashes.  When I think of people today who are experiencing something similar, my mind turns to those in Syria.  There are, however, many circumstances that provoke us to lose hope and feel that all in our life has been destroyed, for example, the death of someone we love, the loss of a job or a family break-up.
Chapters 49-66 were initially addressed to people trying to start anew.  After the Persian King Cyrus defeated Babylon in 539 BCE, Jews began returning to Jerusalem.  Once there, they faced the challenge of rebuilding.  There were setbacks.  Divisions arose regarding the best way to proceed.  The author of Isaiah called this fractioned people to be united and focus on what is most important, namely, the love of God and neighbour.  This is the only foundation on which anything can be built.  Often we need to be challenged to return to basics when we are trying to accomplish something individually or as part of a group.  Divisions can too easily arise in families, Church groups, schools and other communities over inessentials.

The Book of Isaiah illustrates a principle we find throughout Scripture.  Words addressed to people living more that 2000 years ago who had a culture alien to our own are heard today as though they were spoken personally to us.  The message comforts and challenges us.  The words God uttered to His people long ago have not lost their power.