Salt was used in the time of Jesus primarily as a preservative and for the seasoning of food. At a time when there was no modern refrigeration and chemical preservatives, salt was the common preservative.

Meat rubbed with salt would last longer. Fish was preserved by being salted and then carried to more distant villages and towns. The boy’s fish used in the miracle of the feeding of the 5,000 was probably the salted variety. Salt was also used to add taste to otherwise bland food.

We can develop a deeper understanding of what Jesus meant if we look at what the Old Testament says about salt.

Salt was to be included in the offerings made for use in the temple (Ezra 6:9). Why so? The Old Testament Law instructs Israel to ‘add salt to all your offerings’ and to “(s)eason all your grain offerings with salt’ (Leviticus 2:13). Salt was an essential part of temple worship.

The place of salt is continued in the prophecy of Ezekiel in his vision of the new temple of the future (for him, the second temple and perhaps beyond). He wrote regarding the burnt offerings, ‘You are to offer them before the LORD, and the priests are to sprinkle salt on them and sacrifice them as a burnt offering to the LORD’ (Ezekiel 43:24). That which was sacrificed on the altar was to be salted.

Salt was also a key ingredient in the incense used in the temple. Specific instructions were given by God on how to prepare the incense with fragrant spices. The fragrant mixture was then “to be salted and pure and sacred’ (Exodus 30:34-35). The salt that is added contributes to the spiritual quality of the incense. It makes it ‘holy and sacred’. It adds quality to something. This we can see when we come across the phrase ‘covenant of salt’ in the Old Testament.

The covenant that God made with Israel is referred to as ‘an everlasting covenant of salt’ (Numbers 18:19). The covenant, like the holy sacrifices in the temple, is salted – and therefore given a quality that has to do with longevity (like the preserving characteristics of salt) and integrity.

Likewise, God’s covenant with David, the man after His own heart, is described as a ‘covenant of salt’ – and therefore lasts forever (2 Chronicles 13:5). The covenant is salted to indicate its integrity and foreverness and the fact that it is sustained by divine faithfulness and friendship.

KC Pillai has argued that the covenant of salt indicates an irrevocable pledge of faithfulness. Two friends who pledged loyalty to each other would take salt together, and the breaking of such a covenant would result in the death penalty. More than a century ago, Clay Trumbull showed using biblical and anthropological studies that ancient salt covenants were covenants that were permanent and could not be changed.

When Jesus told his Jewish disciples, “You are the salt of the earth”, the weight of what He said must have come from the place of salt in worship and how God’s covenants are described.

Salt connoted permanence, integrity, loyalty, faithfulness and preserving and staying power.

The disciples living in the kingdom are to be to the world like salt that is used to preserve food. The world that is turned against God putrefies, and its condition will rapidly deteriorate if not for spiritual salt that is applied to it through the lives and witness of the children of God.

Wherever they are, God’s children slow down the putrefaction and decay, and in some cases (as seen in history) they have even been able to reverse the decaying process and bring about new transformation and freshness in society.

Consider this:
What did you learn from the way Jesus compared the ministry of Christians in the world with the use of salt? How have you and your ministry been the salt in your community?