“You are the salt of the earth. But if the salt loses its saltiness, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled underfoot”. Matthew 5:13 (NIV)
Jesus was telling his disciples to keep their core values as men and women whose lives have been changed by the hand of God: to preserve what is good, to protect the good things around them from further moral decay and deterioration, and to add a sense of “good” flavor wherever they go.
This is also a reference to the salt of the covenant with the Israelites in general (cf. Leviticus 2:13) and to the Davidic throne in particular (cf. 2Chronicles 13:5) as well as to the lasting provision of the priests who were not part of the land inheritance instituted by Moses and Joshua (Numbers 18:19). The salt of the covenant in the Old Testament have been mentioned in different circumstances, in different times, and involving different beneficiaries and may not have been specifically defined. Nonetheless it carries the full benefit endowed by a lasting ordinance made by God Himself, with the understanding that God will keep His promises in perpetuity no matter what.
For us modern-day believers, this exhortation from Jesus only signifies how important it is to go back and re-examine what we believed at first. If we lose our core values (our saltiness) as Christians, we are no better than the world around us. We must go back to God. As Christians, the day we lose our felt need for God is the day that we lose our purpose. Without purpose, life has no meaning.