In Matthew 5:13-16 Jesus describes his disciples as salt and light.
Salt provides flavour to food; it was used as a preservative in the days before fridges; it can be used to clean wounds; it melts ice to keep pavements safe. Therefore disciples are those who add flavour to society making it 'taste' better. They stop the rot. They bring healing. They will stop you slipping over if you walk on them in the snow.
It is possible that Jesus had the first three of these images in mind in Matthew 5 - it is unlikely that the final image occurred to any of his listeners, but I might be wrong.
Light allows us to see, so that when we walk we don't bump into things or fall over. It allows us to find things that may otherwise be hidden. It is attractive - when you are lost in the mountains you will walk towards a light. So disciples are those who show the way and are attractive to others.
We can't know for sure whether Jesus had one or more of these images in his mind as he spoke about salt and light. But taken as a whole these are positive images. A disciple should have a positive impact on the society in which she or he lives. A disciple will make a difference.
What difference will we make today?
