Isaiah 60:1-3

"Arise, shine, for your light has come, and the glory of the LORD has risen upon you. For behold, darkness shall cover the earth, and thick darkness the peoples; but the LORD will arise upon you, and his glory will be seen upon you. And nations shall come to your light, and kings to the brightness of your rising. "

Isaiah 60 recounts the goodness that is coming to Israel because of the salvation God is about to work. Isaiah speaks in terms of light and darkness. Israel was in darkness, just as lost as the rest of the world, but behold! light is coming. The messiah is here! Rise up, you chosen people, your God has come to save you. And more than that, he will set you up as a beacon of light that will draw nations and kings and all peoples to you.

But more than that, for as the redeemed are drawn into the light of the Gospel, the gospel goes out into the darkness and banishes it forever. So that the culmination of the chapter is this beautiful promise:
"Your sun shall no more go down, nor your moon withdraw itself; for the LORD will be your everlasting light, and your days of mourning shall be ended. "

This is our glorious hope and the reason that we preach the gospel. Nothing is going to stop the light of the good news of Jesus Christ until all darkness of sin is banished and all eyes see the Glory of God. So preach! Take the gospel to the street corners and the school yards and grocery lines and little league meets. Nothing will stop Gods light from going forth an it will reach a full culmination.

O church, arise and put your armor on;
Hear the call of Christ our captain;
For now the weak can say that they are strong
In the strength that God has given.
With shield of faith and belt of truth
We’ll stand against the devil’s lies;
An army bold whose battle cry is “Love!”
Reaching out to those in darkness.
~K. Getty & S. Townend