Thus says the Lord: If you remove from your midst oppression, false accusation and malicious speech; if you bestow your bread on the hungry and satisfy the afflicted, then your light shall break forth like the dawn. “True Fasting” is the title of the 58 ^th chapter of the Book of Prophet Isaiah from which today’s First Reading has been excerpted. The chapter itself is part of the book which is concerned with justice and compassion. The justice championed by the prophets of the Old Testament concerned much more than giving individuals their due, be it wages for work, punishment for evil doing, or respect for human rights. For the prophet’s community, justice referred to living according to the covenantal relationship from which it derived both its essence and existence. Justice ensured that the bond that tied the members of the community to one another and to God was safeguarded. And for a community that had returned from the traumatic experience of exile, justice meant ensuring that the “sins” which had contributed to their being taken into exile was not repeated. From the 58 ^th chapter, we can conclude that these “sins” included injustices such as oppression and neglect of the needy (cf. 58:3b-7). In calling the remnant community to live justice, the Lord was simply reminding them  to re-discover their identity as a people of the covenant. Only by leading just lives were they assured of regaining their place by the side of the Lord as the Lord’s elect (v. 8). This is the very message that Jesus was passing on to his disciples in the Gospel Reading.  
Following the laying out of the new values requisite for belonging to the kingdom (in the Beatitudes, last Sunday’s Gospel Reading), Jesus turns his focus on his disciples. The disciples, those who had already responded to the call and had become his partners in ministry, were henceforth to face head-on the challenge of living the demands of the covenantal relationship that God had made with their ancestors. It was time they realized that their being called and set apart was not for their own benefit but rather for the good of their brothers and sisters (v. 16:  Now that you have become the light of the world, your good deeds must shine before others). As followers and partners of Jesus, what they were taking upon themselves was responsibility. A lot was going to be demanded of, and from them and they needed to be ready for it. 
Jesus likens the disciples to two common household things: salt and lamp-light. It was a comparison that was meant to be easily understood by those gathered to listen because the two were items that could not be missed in even the humblest of households. Salt was used for the seasoning and preservation of food. While salt cannot in itself lose its seasoning or preservation quality, it can be rendered un-usable if it is not properly stored. And when that happens, it is thrown away, for salt is good only if it can be used. On its part, at a time when electricity as we know it today was yet to be invented, a lamp provided the much needed lighting at night. Every single household at the time of Jesus had a lamp. Whereas the wealthier households could afford a lamp for each room or corner of the house, ordinary households had a single lamp only. For such households, the single lamp was always put in a central place on a high pedestal (lamp-stand) so that it could illumine the entire house. 
As the salt of the earth, the disciples had an important role to play in the society. Just as salt brings out the flavor in food, so too were the disciples called and sent to go and make a difference in the lives of the people. The disciples, by accepting to live according to the standards set for them by Jesus in the beatitudes, had become the lamps for the community. It was their responsibility to ensure that once lit, their lights were not extinguished. Moreover, their lights were to be put on a high, central place so that others could be guided by it. ‘ In order that your light does not go off,’ says God through the prophet Isaiah, ‘ share your bread with the hungry, shelter the oppressed and the homeless, and cloth the naked.’
A disciple must become a doer of the word. He/she must be ready to put to practice the teachings he/she learns from Jesus. Embodying the teaching of Jesus becomes the most effective way for a disciple to ‘season’ the earth and provide light for those who are still in darkness. A disciple who fails to embody Jesus’ teachings loses his/her seasoning capability and is thus rendered useless. The Gospel message is a call to action. It is a call that must be answered by the disciple himself in imitation of Jesus Christ whose life can be summed up in one word: ACTION.