Have you ever wondered how Jesus chose the images he used in his parables? What thoughts and feelings would the expression “salt of the earth” have for the people of the ancient world? Salt was one of the most useful and familiar substances for the people of his time, and both of these qualities made it the perfect image for Christ’s preaching.
Before the invention of the variety of cleaning agents we have today, salt was an all-purpose cleaner. Its hard granules helped with scouring, especially while cleaning cookware. Additionally, salt could be used as an exfoliant. The cleansing purpose of salt represents the purging of the spiritual life. We need to be cleansed, often scoured, and Jesus tells his disciples that their words and their lives must serve as a means to purify the earth, that is, the people to whom they are sent.
Especially in warm climates, salt was one of the primary means of preserving foods. Adding salt increases osmotic pressure surrounding the meat, making bacteria and other microorganisms unable to grow, which allows the meat to last longer. If you were not going to eat the whole animal, you would preserve the excess by salting it. The task of spiritual salt, then, is to preserve for eternal life what remains after the scouring. Apostolic preaching must protect those who have been scoured and purified from the temptations and effects of sin, as salt protects food from spoiling.
More than simply cleaning or preserving, salt also enhances. Salt draws out the hidden flavor within food, making it savory and even staving off bitterness. The preaching of the Gospel draws out, by the Holy Spirit, the life of grace and virtue. Likewise, the Christian, as the salt of the earth, elicits acts of faith in others, helping them to live the new and supernatural life they find in Christ Jesus.
Image: Polish Salt Mine Chapel by Sandra Dubek