It prevented the spread of decay in foods. In the same way, we as Christians are to prevent the spread of spiritual and moral decay in the world today. Salt is a symbol of the preserving and purifying power of truth which, as Christians, we possess in Christ. People die, there is no life, the land is barren and unfruitful, and many more problems and complications result from bad water. The salt of biblical truth is that sex outside of monogamous marriages is wrong.
Abstinence is biblical.
Homosexuality is sin. Christians are the new bowl, containing the salt. By speaking the truth directly to the sinful heart of man. The Hebrew word used here is for teens and older. A negative response to God's word brings a curse on those who mock God.