"I could be right as rain. But being right in no way equates to being loving. That’s what God is trying to point out through Isaiah – your good practices cannot erase your bad treatment of God’s beloved. That’s what Jesus is trying to point out – you ARE salt, and you ARE light, but being those things can become impure or blocked if you let it.
But as I mentioned earlier, there is the rest of the message. Isaiah the Poet Prophet brings us full circle back to God. After the lecture, Judah isn’t left hanging in shame and neither are we. We are given a message of hope." (Thomas, "The Other Half of the Message", February 09 2014).