““You are the light of the world—like a city on a hilltop that cannot be hidden. No one lights a lamp and then puts it under a basket. Instead, a lamp is placed on a stand, where it gives light to everyone in the house. In the same way, let your good deeds shine out for all to see, so that everyone will praise your heavenly Father.”
Matthew 5:14-16 NLT
http://bible.com/116/mat.5.14-16.nlt