Chapter 17 of Jesus the Christ continued...
2 Chronicles 13:5
The idea of salt in these passages are many fold. First, salt was a symbol of the covenant between Jehovah and Israel. Also, salt in that area of the world has impurities in it that cause the saltiness to evaporate. While the substance that remains looks like salt, it has little flavor or savor. This represents the self-righteous religious hierarchy of the era. They appeared to be followers of God, but they had lost the spirit of worship only embracing the outward appearance. Insincerity said Jesus, would cause calamity and "in no case [allow anyone to] enter into the kingdom of heaven."
That leads to the question, am I sincere or self-righteous. That old pride is an easy sin into which everyone can slip. We have the truth don't we? That is likely what the Pharisees thought. Yes, truth can set you free, however, skewed vision blinds us to how we let pride twist it. I should guard against pride...but how is this done? Every day without fail, pray with true faith, study God's word, attempt to live according to the Word, repent often, listen to inspiration of the Holy Spirit, and allow Jesus to light the inner light...but doesn't that sound like a Pharisee-ish checklist? That's the problem. Do these things with a singleness of heart, a willingness to follow God's will, and an eye on the kingdom to come.