Ye are the salt of the earth: but if the salt have lost his savour , wherewith shall it be salted ? it is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men. Matt 5:13
Coming from a religious background, many of us.. no, most of us have heard the proverbial 'salt-sermon'. It runs along the self-congratulating idea that Christians are a preservative on Earth.