Sunday, Feb. 9, is the Fifth Sunday of Ordinary Time (Year A). Mass readings: Isaiah 58:7-10; Psalm 112:4-9; 1 Corinthians 2:1-5; Matthew 5:13-16.

In today’s Gospel, Christ uses two images to instruct his followers about the “essence” of discipleship: salt and light. Above all, he uses these images to describe the effect of discipleship. On the one hand, Christ’s disciples are to be a positive, visible force in the world. On the other hand, there is a universal dimension of discipleship — it is the salt of the earth and the light of the world that Christ speaks about, and this indicates that it is not only the Jewish people but also people of all nations who will benefit from the spread of his Gospel though the lives of his disciples.

In addition to these general observations, it is important to examine how Christ is using these images to instruct his disciples about how they are to conduct their lives. In this regard, a piece of chemistry trivia proves useful: The chemical compound Sodium Chloride (NaCl), which we know more commonly as table salt, is one of the most stable substances in nature — its chemical structure is not easily altered, and this means it cannot lose properties such as its salty flavor. This tidbit of information sheds some light on what Christ means when he asks the question: “If salt loses its taste, with what can it be seasoned?” In the context of this passage, this question is meant to express a situation of absurdity; the idea that these small white crystals would lose their essential properties was unthinkable, and yet, theoretically, if that were to happen, it would be absurd to continue to try to use them to flavor and preserve food — the two main purposes for which salt was used in the ancient world.

As the salt of the earth and the light of the world, disciples of Jesus Christ are meant to have a positive impact upon the world by living out the Gospel — something that involves the proclamation of the word as well as the undertaking of good deeds. In other words, if a disciple were not to do these things, that disciple would be as strange as salt that has lost its flavor or a lighted lamp that is placed under a bushel basket. Indeed, though such a person might initially appear to be a disciple of Jesus, failure to proclaim the Gospel in word and deed would indicate a lack of the essence — both the qualities and effects — of a true disciple. It would thus be absurd to rely on such a person to transform the world in the way that Christ asks of his disciples.

Because Christ’s teaching about discipleship in the gospel remains somewhat abstract, we might look to Isaiah’s prophecy of hope in the first reading to concretize it: “Share your bread with the hungry; shelter the oppressed and the homeless; clothe the naked when you see them, and do not turn your back on your own. Then your light shall break forth like the dawn …” (Isaiah 58:7-8). Here we see the prophet describe specific works of mercy: feeding the hungry, sheltering the homeless, clothing the naked and comforting the distressed — in terms of shining forth light into the world, which is precisely what Christ tells his disciples they should do (Matthew 5:16). Moreover, the end result of shining one’s light before others is that they will experience such good deeds as a reflection of the light of God’s mercy and glorify their Heavenly Father. As Isaiah explains, this is because such good deeds are, in fact, a means of disposing oneself and one’s entire community to receive the light and glory of God.

Works of mercy, then, are nothing less than a means by which human beings cooperate in maintaining relationship with God — a God whose Son is visible in the poor, homeless, sorrowing and needy. When we engage in such works of mercy, we not only demonstrate true discipleship by cooperating with Christ’s grace, but we also serve as instruments in God’s saving plan for others by providing them with an opportunity to see the glory of God at work in the world and to praise him for it.

   Dominican Father Jordan Schmidt is an instructor

 in sacred Scripture at the

Pontifical Faculty of the

 Immaculate Conception at the

Dominican House of Studies in Washington, D.C.