"You are the light of the world. A city set on a hill cannot be hidden."
The problem with much of evangelical Christianity is that it wants to be hidden. It wants to remain unnoticed by the world at large. We don't want the hassle -- the political pressure. We try and withdraw from the world and live quiet little lives, not making an impact on the people, cultures, communities, and even nations around us.
This withdrawal orientation has left the political structures and power places for the pagans to inhabit. They then impose their views upon us which then causes us to withdraw further. It is clear that God wants us to light up the world with righteousness and to give glory to God.
you are the light of the world
Jesus is addressing his disciples about what is true of them – that you, not He, are the light of the world! Notice that Jesus does not say “If the light that is in the light is darkness then how great is the darkness.” He says that later. Jesus does not castigate them for not being light; he castigates them for trying to be hidden. God's people do glow through their righteous acts; it is just that they keep trying to hide it!
Just as when we discussed salt, the way that we are more light is to live out the beatitudes. We are to be humble, mourning, radically flexible, doing clearly right things, merciful, pure to the core, bringers of harmony, willing to suffer for righteousness and for Christ's name.
Notice that He says that they and we are the light of the world. In other words, the world needs to see our light -- the reflected glory of God in our lives. We need to be like the moon, reflecting back God's grace, mercy, power, and direction into the world.
a city set on a hill cannot be hidden
A collection of people constantly doing the right thing and doing extraordinary things cannot be hidden, so don't try. In fact, the whole world needs to see what is going on.
There is in this verse the interesting idea that God wants to display His people. He is constantly trying to push them up so that others see them. Unfortunately, many Christians are trying to hide from the public lest they be contaminated.
Jesus' methodology is exactly the opposite of our advertising culture. Our culture says try and reach everybody with the message as soon as you can. Jesus’ method seems to be to try and penetrate a few people deeply with the message so that they glow with it. Then it will spread. But it is the depth of the message that is the message.
This would suggest that the modern American church philosophy of a mile wide and an inch deep would not have Jesus' support. He, however, does not want an inch wide and a mile deep either. In fact, He is trying to guard against religious isolationism when He says, “You are the light of the world!” The reflected glow of God's nature in the righteous acts of the true Christian followers is all the light that non-Christians will get. A Christian’s light is what allows non-Christians to realize that there is a supernatural dimension. There IS a God! There IS a next life! There IS good and evil! And sin DOES exist!
Notice that Jesus said, “You are the light of the world.” Light shines! As it engages with those around it, it does not fight with those around it -- it just illuminates! We simply need to do what we do, reflecting the wonder of the God who works so much in us. Notice also that Jesus suggests with this statement, and the one before about salt, that we are the infectious agent and not the world around us. We have the power to change the world when we allow God to flow through us and live the qualities that Christ exhibited.