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. Isaiah 40:4-5
Isaiah 40:3-8, which today’s passage is part of, is like much of the prophecy in Isaiah because it has several levels of meaning and application: (1) They refer to the Jews’ return and restoration from exile (after they had been conquered and deported from their homeland by the Babylonians as part of God’s judgement). (2) They also refer to the coming of Messiah and the salvation he would bring. (3) Finally, they refer to the complete liberation of God’s people at the end of time, when God establishes a new heaven and a new earth where he will reign for eternity with his people.
Now that we understand the context around today’s passage we can actually look at today’s passage. Verse 4 tells that God is getting everything ready for something big to happen. That is what all the talk about valleys being lifted up, mountains being made low and rugged places being made smooth. This is all symbolism for God preparing the way for his great plan of salvation to take place. And then we come to verse 5 which tells us “the glory of the Lord will be revealed.”
God knew that everything that had happened in preparation for the revealing of his glory would not be enough to convince people of his wonder and greatness. So, in the context of the people of Israel. They would see the wonder and greatness of the Lord when he freed them from Babylonian captivity. But to the rest of the world he would reveal his glory and power in an even greater way through Jesus Christ, who can free people from captivity to sin and bridge the gap of separation from God. And this glory and power will be revealed even further when Christ returns to establish his kingdom here on earth once and for all.