In writing to the Christians living in Colosse, a city in western Turkey, Paul addressed the unique revelation that they, as converted Christians, had received the Holy Spirit—that is, that Jesus Christ was living within them through the Holy Spirit--and this fact was their assurance of the hope for eternal life.
In verses 24 and 25 of Colossians 1, Paul speaks of the Church of God by calling it the “body” of Christ. He also addresses the fact that he, Paul, had become a minister of the word of God. In this context, he continues addressing these faithful brethren:
"You are the light of the world. A city that is set on a hill cannot be hidden."
-Matthew 5:14