Salt, light, and law

Just listening to Sunday's sermon text which is from Matthew 5:13-20. It goes like this:

‘You are the salt of the earth; but if salt has lost its taste, how can its saltiness be restored? It is no longer good for anything, but is thrown out and trampled under foot.

‘You are the light of the world. A city built on a hill cannot be hidden. No one after lighting a lamp puts it under the bushel basket, but on the lampstand, and it gives light to all in the house. In the same way, let your light shine before others, so that they may see your good works and give glory to your Father in heaven.

‘Do not think that I have come to abolish the law or the prophets; I have come not to abolish but to fulfill. For truly I tell you, until heaven and earth pass away, not one letter,^* not one stroke of a letter, will pass from the law until all is accomplished. Therefore, whoever breaks^* one of the least of these commandments, and teaches others to do the same, will be called least in the kingdom of heaven; but whoever does them and teaches them will be called great in the kingdom of heaven. For I tell you, unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven.

Such raises in my own mind these questions:

• What are the various ways salt is used? How does this add to the meaning of Jesus' words: 'you are the salt of the earth'?
• What are the various sources of light? uses of light? What does this say about Jesus saying, 'you are the light of the world'?
• How are we living out the law--the love--of God? What needs to be taken away or added to our behavior so that we live out the love of God for all the more?

Let's just say Jesus represents, and ultimately is, a challenging love for all.