You are the light of the world. A city set on a hill cannot be hidden. Nor do men light a lamp only to put it under a bushel basket; they put it on a stand where it gives light to all in the house. The Lord called his disciples the salt of the earth because they seasoned with heavenly wisdom the hearts of men, rendered insipid by the devil. Now he calls them the light of the world as well, because they have been enlightened by him, the true and everlasting light, and have themselves become a light in the darkness.  Since he is the Sun of Justice, he fittingly calls his disciples the light of the world. The reason for this is that through them, as through shining rays, he has poured out the light of the knowledge of himself upon the entire world. For by manifesting the light of truth, they have dispelled the darkness of error from the hearts of men. Moreover, we too have been enlightened by them. We have been made light out of darkness as the Apostle says: For once you were darkness, but now you are light in the Lord; walk as children of light. He says another time: For you are not sons of the night and of darkness, but you are all sons of light and of the day.