In the New Testament, the Lord Jesus urged His disciples to have salt in themselves (Mark 9:50). This exhortation occurs at the end of various warnings about sin and temptation that conclude with the solemn reminder that a day of judgment lies in the future when “everyone will be salted with fire” (v. 49). Christ’s followers are therefore to possess the good qualities of salt and not let them dissipate (v. 50). The fire of God’s judgment will salt and purify the world. Believers should therefore be a purifying influence in the world through their Christlike testimony. Believers are, after all, the salt of the earth (Matt. 5:13).
Salt appears throughout the Bible, and people most readily identify it with its ability to season food that would otherwise be bland. Salt is also a well-known agent in the preservation of food and a means of purification. The prophet Elisha employed salt to heal a spring and remove impurities found in the water (2 Kings 2:20–21). Ezekiel’s reference to the practice of rubbing a newborn baby with salt was possibly to prevent infection (Ezek. 16:4). Salt in the ancient world was very expensive, and people used it sparingly and with care. These multifaceted characteristics of salt as a valuable, taste-enhancing, preserving, and purifying agent play varying roles in the passages where this compound appears.
The first reference in the Bible to salt as an ingredient occurs in Exodus 30:35. The perfumer who made incense for the altar combined sweet spices with frankincense and seasoned the mixture with salt. Since this incense was not for consumption, salt was not a flavor additive. It did, however, depict both purity and preservation. Incense wafting heavenward from the altar was a symbol of prayer (Ps. 141:2; Luke 1:10; Rev. 5:8). Salt added to the mixture reminded Israel that when the priest burned this incense on the altar, their prayers were pure before God and not forgotten. As Christians, we pray in Jesus’ name so that all the virtue and value of His atoning sacrifice will purify our prayers. We also pray with the assurance that the Lord never forgets what we pray (Ps. 38:9; Rev. 8:3–4).