Matthew 5:13-16 (NASB)
13 “You are the salt of the earth; but if the salt has become tasteless, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled under foot by men.
14 “You are the light of the world. A city set on a hill cannot be hidden; 15 nor does anyone light a lamp and put it under a basket, but on the lampstand, and it gives light to all who are in the house. 16 Let your light shine before men in such a way that they may see your good works, and glorify your Father who is in heaven.