Those who heard Jesus speak would have understood the meaning and tradition behind the idea of being ‘salt of the earth’. In the same way as salt prevents decay and corruption, so the witness of Christians who live a life in the power of the Holy Spirit protects the world and society from decay and corruption. It also adds much needed flavour to society. Too much salt in our food can make us thirsty. St. Augustine once wrote, ‘O Heavenly Father, you have put salt in our mouths that we may thirst for you.’ the work of the Holy Spirit is to create within us a thirst for the things of God: for union with God, for communion with him and for grace to live a life which is holy and pleasing to him. Jesus also call us to be ‘the light of the world. We are to be heralds of the gospel.