Jesus looks at His disciples and says, "You are the salt of the earth... You are the light of the world."  Jesus' first sermon recorded in Scripture—commonly known as the Sermon on the Mount, found in Matthew chapters 5, 6, and 7—He addresses His disciples in a remarkable way. Instead of giving them instructions about their activity (what they're supposed to do), He gives them affirmation about their identity (who they're supposed to be).