This is a fitting passage with which to close our reading in the Old Testament. In many ways it takes us full circle, from the wilderness of the Exodus to the beauty and blessing of the New Heavens and New Earth.
In verse 1, Isaiah is referring back to the wilderness wandering that God’s people experienced after they left Egypt and before they entered the Promised Land. They were pilgrims, wandering in the desert. The desert is a dry, uninhabitable place, but God continually provided for them for forty years. It did bloom and blossom.
The world is no longer the garden it was in the beginning. The world has deserts because of sin. The world itself waits for redemption (Rom. 8:20-21). Isaiah is giving a picture of what this redemption will look like. The world itself will bloom and blossom abundantly, so much so that it will rejoice with joy and singing!
How will this happen? The glory of the Lord will bring it. A voice cries: “In the wilderness prepare the way of the Lord; make straight in the desert a highway for our God. Every valley shall be lifted up, and every mountain and hill be made low; the uneven ground shall become level, and the rough places a plain. And the glory of the Lord shall be revealed, and all flesh shall see it together, for the mouth of the Lord has spoken” (Isaiah 40:3–5). Everyone will see the glory of God when the one for whom the way has been prepared comes. Jesus is that person. He began that process at his first coming, and he will complete it at his second coming.