A voice of one calling:
In the wilderness prepare
the way for the Lord;
make straight in the desert
a highway for our God.
Every valley shall be raised up,
every mountain and hill made low;
the rough ground shall become level,
the rugged places a plain.
And the glory of the Lord will be revealed,
and all people will see it together.
For the mouth of the Lord has spoken.
Depending on which English translation you read, the wording will vary slightly; Luke seems to have used a Septuagint reading which yields a slightly different English rendering. In any case, however, the primary meaning of the text has nothing directly to do with Christmas, Advent, or the birth of Jesus. Perhaps even more surprisingly, its topic is civil engineering.
Planning and constructing roads, bridges, dams, and the foundations for large buildings - that is civil engineering. Knowing about different types of cement and concrete, steel and dirt - that's how a civil engineer calculates his designs. If you read our text from Isaiah carefully, that's Isaiah's theme as well.
Isaiah was writing about what would happen when the captives - Israelites who'd lived in the kingdom of Judah, but been taken as POW's to Babylon when Nebuchadnezzar's Babylonian armies besieged Jerusalem - finally got their freedom back. When that city fell, the rest of the countryside was also taken by the invading army. Between 598 B.C. and 583 B.C., groups of Judaeans were deported. They lived in Babylon, at first under the reign of King Nebuchadnezzar, then under other later rulers, for approximately 70 years.
King Cyrus of Persia was bad news for the Babylonians, but good news for the captives from Judaea. In 538 B.C., he conquered Babylonia, and allowed them to return to their homeland. The Persians were known for building a system of roads which connected the various territories which they first conquered, and then incorporated into their expanding empire. It is about these roads that Isaiah writes.
Filling in low places, carving notches to create passes through hillsides, straightening winding roads into direct highways: Isaiah is describing the civil engineering projects of the Persians. The captives would have a good trip home.
Although this early freeway project is the primary meaning of the text, it is not the only meaning. Although "green" politics made its appearance in the second half of the twentieth century, God was already recycling long before that. Isaiah received a prophetic message, and even after the end of the Babylonian Captivity, the passage would be reused.
The first time that Isaiah's text was recycled was concerning John the Baptist, as Luke recounts. "Prepare ye the way for the Lord!" meant, not Persia building physical roads for Israelites returning from servitude, but rather now it was recycled to mean that the Messiah was arriving. John's task was to prepare Israel for the advent of its King.
But the recycling didn't stop there. This text finds a continual application in the heart and mind of every human: we are invited to receive the Messiah and the salvation He gives. We receive Him in different ways at different times - He is constantly approaching us - through His written Word, through bread and wine, through the water of baptism. Again and again, Jesus shows up in our lives. Prepare the way for Him!
And, of course, the text from Isaiah is recycled seasonally: every year during the time of Advent, the passage is read again, and we are reminded of God's magnificent sweep through history - He keeps approaching people with His saving love, rescuing the captives from Babylon, rescuing us from the consequences of our own sinfulness.
There are probably more and other ways in which this passage has been, is being, and will be recycled: other ways in which Isaiah's words, "prepare the way for the Lord!" break into earthly human existence with the power and light of God's gracious intervention in our lives.
