We're pragmatic and aloof. We're even dualistic in our ethics. In all of our talk of tolerance, there is a deep core of racism. He warns us not to lose our saltiness. Sometimes it can acquire a stale or alkaline taste because of the gypsum and other minerals that are mixed with it.
Salt can become tasteless because of a process of contamination or infiltration.
That, I believe, is Jesus' point in using this metaphor. That's an ideology that needs to be unmasked and dealt with. Blessings are given to Christians so that we, in turn, may be blessings to other people. I have made you into something so that you indeed are the salt of the earth and the light of the world. In Presbyterians Today , there is an article about Millicent Gordon.