Matthew 5:13-15

Ye are the salt of the earth: but if the salt have lost its savor, wherewith shall it be salted? it is thenceforth good for nothing, but to be cast out and trodden under foot of men. Ye are the light of the world. A city set on a hill cannot be hid. Neither do men light a lamp, and put it under the bushel, but on the stand; and it shineth unto all that are in the house.