Let Us Walk in the Light
—A theme of Isaiah
One of the great themes of Isaiah is spiritual light and darkness. The early chapters of Isaiah include a call to walk in the light of the Lord, and make three strong statements about light and darkness, including a prophecy about Jesus...
“Come, house of Jacob, let us walk in the light of the Lord” (Isaiah 2:5).
This still remains God’s call and a condition of fellowship with him. John writes to Christians that "God is light and in him there is no darkness at all... If we walk in the light as he is in the light we have fellowship with one another and the blood of Jesus Christ his Son cleanses us from all sin" (1John 1:5-7).
1 Woe to those who darken the light
Isaiah 5:20
"Woe to those who call evil good and good evil, who put darkness for light and light for darkness" (Isaiah 5:20).
It is characteristic of spiritual darkness that what God sees as abominable, men see as honourable. What is evil is approved of as good. Paul, having listed several evil practices, goes on to say that people "not only do such things but also give hearty approval to those who practice them" (Romans 1:29-32).
2 God's law gives light
Isaiah 8:20
"To the law and to the testimony! If they do not speak according to this word, they have no dawn" (Isaiah 8:20).
People who have no dawn remain in the night. They do not see the light of day. People who have no light in them — who have experienced no sunrise in their soul — can be enlightened by only one source, the law and the testimony of God. Today of course God's law or new covenant has come to us through Jesus who was the light of mankind bringing grace and truth (John 1:4-5, John 1:17-18).
3 The Light Shines on Everyone
Isaiah 9:1-2, Matthew 4:12-16
"...by the way of the sea, on the other side of the Jordan, Galilee of the Gentiles. The people who walk in darkness shall see a great light; those who live in a dark land, the light will shine on them" (Isaiah 9:1-2).
Galilee, the land where the tribes of Naphtali and Zebulun had settled, was one of the first areas to be captured and conquered by the King of Assyria (2Kings 15:29).
However the real "yoke" and the "oppressor" of these people (Isaiah 9:4) was not an invading foreign nation. Their yoke was sin. Their oppressor was Satan, who oppresses the whole world. The spiritual forces of darkness (Ephesians 6:12) had long been at work speading ignorance, idolatry, and confusion (Isaiah 9:16), and they are still doing so today the world over (1John 5:19-20).
Isaiah looks forward to a day when the Son of God will sojourn in Galilee and bring the light of his gospel to its people. But that was only the beginning. Jesus sent his apostles, "men of Galilee" to the remotest parts of the earth, so the gospel might spread its light in all the world (Acts 1:8-11, Acts 2:7-11, Mark 16:15).
Today the world lies in darkness. "The god of this world has blinded the eyes" of so many people, yet for those who wish to see, "the light of the gospel of the glory of Christ who is the image of God" shall illumine them. He has "shone in our hearts to give the light of the knowledge of the glory of God in the face of Christ" (2Corinthians 4:4-6).