You are the light of the world.
Matthew 5:14,16
“You are the light of the world. A city that is set on a hill cannot be hidden. Let your light so shine before men, that they may see your good works and glorify your Father in heaven.
Matthew 5:14,16
Then Philip went down to the city of Samaria and preached Christ to them. And the multitudes with one accord heeded the things spoken by Philip, hearing and seeing the miracles which he did. For unclean spirits, crying with a loud voice, came out of many who were possessed; and many who were paralyzed and lame were healed. And there was GREAT JOY in that city. 
Acts 8:5-8
The people who sat in darkness have seen a great light, And upon those who sat in the region and shadow of death Light has dawned.” 
Matthew 4:16
A light that shines brings joy to those living in darkness. To a blind there is no greater joy than to be able to see, to the lame there is no greater joy than to be able to walk, to the barren there is no greater joy than to get pregnant and deliver a baby.
Then God said, “Let Us make man in Our image, according to Our likeness; let them have dominion over the fish of the sea, over the birds of the air, and over the cattle, over all the earth and over every creeping thing that creeps on the earth.” 
Genesis 1:26
“Assuredly, I say to you, whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven. “Again I say to you that if two of you agree on earth concerning anything that they ask, it will be done for them by My Father in heaven. 
Matthew 18:18-19
You are to the earth, what God is to heaven
All authority in heaven belongs to God, while all authority on earth is given to man.
Arise, shine; For your light has come! And the glory of the Lord is risen upon you. 
Isaiah 60:1
To shine simply means to exercise your authority to bring joy into the life of someone sitting in darkness, to deliver someone from the bonds of pain and suffering and to give hope to the hopeless. When you exercise your authority on earth as Son of God, God establishes it in the heavenly realm. And what God establishes in the heavenly realm is seen and experienced in the earthly realm.
Sadly today, Christians are become as Job says …And the flame of his fire does not shine. The light is dark in his tent… Job 18:5-6. Like a candlestick having a flame but no light.
