Here comes the Queen.

A number of years ago Queen Elizabeth II visited the city we were living in at that time.  She was given the royal tour and one event on that tour was a visit to the Amethyst Mine.  This mine was near the lake where my in-laws had a cottage.  In preparation for her visit to the mine the road was upgraded.  It was no longer a gravel road but new surface was put down so the road was a smooth road.
Isaiah says in Isaiah 40:3 - 5, 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.”

Luke quotes this prophecy and shows that it is fulfilled in John the Baptist.  What is the highway?  It is repentance.  When the Queen was coming they prepared the roads, we are told to mend our hearts.  We must repent to prepare the way for the coming of the Lord.