"You are the salt of the earth; but if salt has lost its taste, how shall its saltness be restored? It is no longer good for anything  except to be thrown out and trodden under foot by men. "You are the light of the world. A city set on a hill cannot be hid. Nor do men light a lamp and put it under a bushel, but on a stand, and it gives light to all in the house. Let your light so shine before men, that they may see your good works and give glory to your Father who is in heaven. Matthew 5:13-16

The addressees here are those whom the Beatitudes called into the grace of discipleship of the Crucified. Those who were called blessed in the Beatitudes, while being considered worthy of the kingdom of heaven, obviously nevertheless appeared to be utterly unworthy of life on this earth,¹ or to be superfluous. Here, now, they are designated by the symbol of a substance which is indispensable for life on earth. They are the salt of the earth. They are the earth’s most noble possession, its most precious asset. Without them, the earth cannot continue to live. The earth is kept alive by salt. For the sake of precisely these poor, ignoble, weak, whom the world rejects, the earth itself lives. It destroys its own life by expelling the disciples, and—a miracle!—precisely for the sake of these outcasts the earth is permitted to live on. This “divine salt” (Homer)² maintains its efficacy. Its effects permeate the whole earth. It is the earth’s substance.

Thus are the disciples not only directed toward the Kingdom of Heaven, but also reminded of their mission on earth. As those bound only to Jesus, they are directed to the earth, whose salt they are. By calling not himself, but his disciples the salt of the earth, Jesus assigns to them an activity on the earth. He draws them into his own work. He remains among the people of Israel while the disciples are commissioned to work on the entire earth.³ Only insofar as that salt remains salt, and maintains its purifying, seasoning powers, can it maintain and preserve the earth. For its own sake as well as for the earth’s sake, salt must remain salt, and the congregation of disciples must remain what through Christ’s call it really is. Its activity on earth and its preserving power will consist in remaining true to its calling. Salt is supposed to be imperishable, and thereby an enduring power of purification. This is why the Old Testament uses salt in sacrifices, and why in the Catholic baptismal rite salt is put into the child’s mouth (Exodus 30:35; Ezekiel 16:4). The guarantee of the permanence of the community of faith resides in the imperishable quality of salt.

“You are the salt”—not: You should be the salt! It is not for the disciples to decide whether they are or are not to be salt. Nor is any appeal made to them to become the salt of the earth. They are that salt, whether they want to be or not, in the power of the call they have encountered. You are the salt—not: You have the salt. It would be an unwarranted abbreviation were one to follow the Reformers and equate the disciples’ message with the salt.⁴ What is meant is their entire existence insofar as it is grounded anew through Christ’s call to discipleship, this existence of which the Beatitudes speak. Those who have been called by Jesus and stand in his discipleship are, through precisely that call, the salt of the earth in their entire existence.

The other possibility, however, is that the salt loses its taste, and ceases to be salt. Its activity ceases. And then, indeed, it is good for nothing except to be thrown away. That is the distinction of salt. Every thing must be salted. But salt that has lost its taste can never again be salted. Everything, even the most rotten stuff, can be saved by salt; only salt itself that has lost its taste is hopelessly ruined.⁵ That is the other side. That is the threatening judgment hovering over the community of disciples. The earth is to be saved by the community of faith; only the congregation that ceases to be what it is is hopelessly lost. The call of Jesus means being the salt of the earth or being destroyed. Either follow in discipleship or the call itself will annihilate the person called. There is no second chance for being saved. There cannot be.

Along with Jesus’ call, the congregation of disciples receives not only the invisible efficacy of salt, but also the visible radiance of light. “You are the light”—again, not: You should be the light. The call itself has made them into this. Nor can it be otherwise now; they are a light that is seen. If this were not so, the call itself apparently would not be with them. What an impossible, nonsensical goal it would be for Jesus’ disciples, for these disciples, to want to become the light of the world! They have already been made such by the call itself, and within discipleship itself. And again, not: “You have the light,” but “You are the light!” The light is not something given to you, for example, as your proclamation, but rather you yourselves are that light. The same one who says of himself in direct speech, “I am the light,”⁶ says to his disciples in direct speech: You are the light in your entire lives insofar as you abide in my call. And because you are the light, you can no longer remain hidden, whether you want this or not. Light shines, and the city built on a hill cannot be hid. It cannot. It is visible from afar, either as a secure city or as a guarded citadel or as collapsed ruins.

This city on the hill—what Israelite will not think of Jerusalem, the city built on high!⁷ —is the congregation of disciples itself. Those who follow are now no longer faced with any decision of this sort. The only decision relevant to them has already been made. They must now be what they are, or they are not followers of Jesus. Those who follow are the visible community of faith. Their act of following, of discipleship, is a visible activity singling them out from the world—or it is not discipleship. And this discipleship is as visible as light in the night, as a hill on the plain.

To flee into invisibility is to deny the call. A congregation of Jesus that seeks to be an invisible congregation is no longer a congregation of disciples. “No one after lighting a lamp puts it under the bushel basket, but on the lampstand.” That is the other possibility, namely, that the call is denied by consciously concealing the light and extinguishing it under the bushel basket. This bushel basket under which the visible community of faith hides its light can be both fear of human beings and conscious accommodation to the world for whatever purpose—for missionary purposes or because of misunderstood love for human beings.

But it may also—and this is even more dangerous—be a so-called reformational theology that even dares to call itself theologia crucis,⁸ a theology which is characterized by a rejection of “Pharisaic” visibility for the sake of “humble” invisibility in the form of total accommodation to the world. The mark of the community of faith here is not that it is visible in some extraordinary form, but rather that it lives up to the iustitia civilis.⁹ That the community’s light not shine has here been made into the criterion of Christian existence. But Jesus says: Let your light shine before the Gentiles. In any event, it is the light of Jesus’ call that shines here.

What kind of light is this light in which these disciples of Jesus, the disciples of the Beatitudes, are to shine? What kind of light is to come from that particular place to which the disciples alone have a claim? Considering that the disciples stand beneath the invisible and hidden cross of Jesus, what does this have to do with the light that is to shine? Does not the very fact that the cross is hidden imply that the disciples, too, are to remain concealed rather than stand in the light? It is an evil bit of sophistry that concludes from the cross of Jesus that the church is to accommodate itself to the world.

Would it not be clear to an unsophisticated listener that precisely there, on the cross, something extraordinary has become visible? Or is all this perhaps iustitia civilis, is the cross itself accommodation to the world? Is the cross not something that to the horror of others became scandalously visible precisely in its obscurity? Is it not visible enough that Christ is rejected and must suffer, that his life ends before the city gates on the hill of shame?¹⁰ Is this invisibility?

It is in this light that the disciples’ good works are to be seen. It is not you, but your good works that others should see, Jesus says. What are these good works that can be seen in this light? They can be no other than those Jesus himself created in them when he called them, when he made them into the light of the world beneath his cross: poverty, life as a stranger, gentleness, peaceableness, and finally also persecution and rejection, and in all this especially one thing, namely, to bear the cross of Jesus Christ.

The cross is the peculiar light that shines and in which alone all these good works of the disciples can be seen. None of this says anything about God becoming visible. It is the “good works” that are meant to be seen, so that over them people give glory to God. The cross becomes visible, and the works of the cross become visible. The poverty and renunciation of the blessed become visible.

In view of the cross and such a community of faith, however, it is no longer humankind that can be praised, but God alone. If these good works were actually human virtues, then glory would be given to the disciples themselves rather than to God. As it is, however, there is nothing to praise in the disciples who bear the cross, or in the community of faith whose light thus shines and that stands visibly on the hill—in view of their “good works” it is alone the Father in heaven who is praised. Thus do they see the cross and the congregation of the cross and believe God. That, indeed, is the light of the resurrection.

Notes:

1. Beginning in 1939, the evaluation of life as “unworthy of life” in the sense of the “Law for the Prevention of Descendants with Hereditary Diseases” (June 15, 1933) cloaked euthanasia activities in the Third Reich.
2. Cf. Iliad 9.214.
3. Matt. 15:24 and the commandment to evangelize in Matt. 28:18–20.
4. Martin Luther: “With the word salt he [Jesus] shows them what their [the addressees’] office is to be.”
5. Cf. Martin Luther, Weekly Sermons on Matthew 5–7: There is no greater “ruin of Christendom than when the salt with which one must season and salt everything else itself loses its taste.”
6. John 8:12.
7. “O Jerusalem, city built on high . . . ,” a hymn modeled after Rev. 21:1–3 by Johann Matthaeus Meyfart (1590–1642).
8. English: “theology of the cross.”
9. English: “civil justice.”
10. Cf. Heb. 13:12f.

In the seminary at Finkenwalde Bonhoeffer taught the importance of shared life together as disciples of Christ. He was convinced that the renewal of the church would depend upon recovering the biblical understanding of  the communal practices of Christian obedience and shared life. This is where true formation of discipleship could best flourish and mature. Bonhoeffer’s teaching led to the formation of a community house for the seminarians to help them enter into and learn the practical disciplines of the Christian faith in community. 

In 1937 Bonhoeffer completed two books, Life Together and The Cost of Discipleship. They were first published in German in 1939. Both books encompass Bonhoeffer’s theological understanding of what it means to live as a Christian community in the body of Christ.He was arrested by the Gestapo in April 1943. On April 8, 1945 he was hanged by the Gestapo as a traitor in the Flossenburg concentration camp. As he left his cell on his way to execution he said to his companion, "This is the end – but for me, the beginning of life."