You are the salt of the earth; but if salt has lost its taste, how can its saltiness be restored? It is no longer good for anything, but is thrown out and trampled under foot. You are the light of the world. A city built on a hill cannot be hid. No one after lighting a lamp puts it under the bushel basket, but on the lampstand, and it gives light to all in the house. In the same way, let your light shine before others, so that they may see your good works and give glory to your Father in heaven.
I was researching the various facets of salt to understand why Jesus compared us to this compound, and discovered some really fascinating stuff that I am sure will interest you. Did you, for instance, know that in the time of the Roman Empire, soldiers were paid in salt? This gave rise to the expression, 'He is worth his salt.'
Now, we are not paid our wages in salt (thank goodness!) but salt remains a good indicator of our worthiness, especially in the Christian context. I spend some of my time in the kitchen and have noticed that unless I am making a dessert or a sweet dish, every recipe, with very rare exception, requires salt to be added to the preparation otherwise it is flat and tasteless.
Jesus tells us we are the salt of the earth, needed to make that essential difference. How do we do this? By reflecting the character of Jesus. When he walked upon the earth, he brought so much flavor to it. As his representatives — Scripture calls us ambassadors of Christ (see 2 Corinthians 5:20) — we need to be as flavorful.
How? By being people of love, joy, peace, patience, kindness, goodness, gentleness, faithfulness, and self-control. These are ingredients solely lacking in the world, and you just have to look around you to see the truth of that. This makes the world flavorless. But, just like it takes just a sprinkling of salt to make food tasty, all it takes is a sprinkling of these ingredients to make the world a better place.
And, just like people want another helping of a dish that is tasty, so also will people who have a taste of Christ want more of him. I came to Christ for this very reason. Sitting in a jail cell, having lost every single thing I had in my life, there sat a man across me with a Bible and a look of peace on his face that made him look beatific. Since I had never known peace, I went to him for a taste of it, and discovered Jesus.
I have never stopped wanting a taste of him ever since. It will be the same for everyone. So, be the salt of the earth.