In Matthew 5:13-16 we find that Christians are two things: salt and light. We know that salt is a preservative meant to keep rot and decay away. That is exactly the Christian's job as a follower of Christ. The salt is to keep society and culture from plunging headlong into decay. This is only accomplished by Christians looking different than the world and staying true to Scripture, yet when Christians do not act differently they become worthless, good for nothing but to be trampled on.