The Sermon on the Mount is a compendium of the Lord’s teaching. After the Beatitudes we have two parables which differ in imagery but have similar implications: salt and light.  Salt purifies and preserves.  It is essential for life.  With the commercial mining of salt we take its availability as a cheap commodity for granted but in ancient times it was not easily extracted from the rock or sea water and was so valuable that it was the medium in which Roman soldiers were originally paid – ‘salarium’.  Once the salt has been extracted the surrounding debris is useless.  We are to cleanse and provide savour to our world.  Christ is the Light of the World.  We are to be lamps allowing his light to shine out through us and help others see the way.  If we are like individual candles, the Church should be like a sparkling chandelier!  In our first reading, Isaiah sets out conditions for this to happen.  It is by meeting the needs of the poor and bringing an end to violence that our integrity will go before us and our light shine out in darkness.