Grace, mercy, and peace to you from God our Father and the Lord Jesus Christ!  Amen.  Last week we heard Jesus pronounce blessing upon his disciples—upon us!—in the Beatitudes (Matthew 5:1-12).  Whether we feel it or not, we are blessed because Jesus calls us blessed.  His Word creates the reality it speaks into being.

Today we continue to wend our way through the Sermon on the Mount as Jesus tells his disciples of their significance, even as they are downtrodden by a world that rejects the poor in spirit, puts its boot on the neck of the meek, and congratulates itself over the persecution of the church.

“You are the salt of the earth, but if salt has lots its taste, how shall its saltiness be restored?  It is no longer good for anything except to be thrown out and trampled under people’s feet” (Matt. 5:13, ESV).[1]  It used to be a high compliment to call someone “the salt of the earth.”  But what does it mean?  Salt is an essential mineral for the human body.  All animals need salt to survive.  It’s one of the electrolytes you will find in sport drinks because the body needs salt to carry out its biological functions.

In the ancient world, salt was prized so highly that under the old barter system, Roman soldiers were often paid with salt instead of coin.  In fact, our English word salary comes from the Latin word salarium, which means a payment of salt (or sal).  According to historians, in the ancient and medieval world, salt was sometimes called “white gold.”[2]  It was so essential that it could pass for payment.

Not only is salt necessary as a nutrient, but in the pre-modern world, before the invention of refrigeration and canning, people used salt to preserve fish and meat for later consumption.  Meat could be dried out with salt and kept from spoiling.  (Think of beef jerky!)

So by calling his disciples “the salt of the earth,” Jesus means that the Church is the thing that preserves life in the world.  The Church does not retreat from the world and abandon it to destruction.  Rather, the disciples of Jesus bring life to those around them.  And, in fact, the only reason why God has not already destroyed the world is because he is waiting for the full number of his elect to be counted.  There aren’t enough Christians yet.  So in the meantime, we preserve the world.

Yet notice that Jesus does not say, “Be salt” or “Become salt.”  He says, “You are the salt.”  Jesus uses the indicative mood, not the imperative mood.  His word carries not the weight of command but simply speaks of the reality that exists—the reality that he created by blessing us already in the Beatitudes.  Whether you know it or not, Jesus’ disciples are the salt of the earth.  You are the salt of the earth.  The world needs the disciples of Jesus in order to find its life in Christ.  That is why Dietrich Bonhoeffer writes: “The Church is the Church only when it exists for others…not dominating but helping and serving.  It must tell men of every calling what it means to live for Christ, to exist for others” (Letters and Papers from Prison, emphasis added).  Or, as the Ft. Wayne seminary often likes to say, the Church exists “for the life of the world.”

But what if we do not want to live for others?  What if salt loses its saltiness?  Jesus says that it is no longer good for anything except to be thrown away.  This sounds like a strange thing to say.  We wonder how salt can lose its saltiness.  Sodium chloride does not lose its properties.  This ionic compound does not easily melt or evaporate.  The melting point of salt is 1,474ºF.  That’s twice the surface temperature of Mercury, the planet closest to the sun!  Salt cannot stop being salt!

But in the ancient world, salt rarely existed in the pure white form we have in our salt shakers in the kitchen at home.  Salt was nearly always mixed with other minerals from the mines, and as containers of salt sat out on tables, they would become diluted with dust from the air and dirt from people’s hands.  Eventually, it was possible that a container of salt would become so badly mixed that it didn’t even taste like salt before, and it no longer existed in a high enough concentration to do its job of flavoring food and preserving meat.  And so it would be tossed out into the street to be trampled underfoot.

Here is a warning for the disciples of Jesus: if we do not remain salty through faith in the crucified, then our spiritual salt can become diluted by sin and distractions.  Eventually, we may stop believing altogether and lose our “saltiness.”  Then we are good for nothing except to be tossed out of the kingdom.  Apostasy is a real danger for those who do not remain filled by Jesus.  But you are the salt of the earth.  So stay salty, friends.

Jesus continues: “You are the light of the world.  A city on a hill cannot be hidden.  Nor do people light a lamp and put it under a basket, but on a stand, and it gives light to all in the house” (Matt. 5:14-15).  Dear brothers and sisters in Christ, you are the light of the world!  Elsewhere in the Gospels, Jesus will declare himself to be the light of the world (cf. John 8:12; 9:5).  But here in the Sermon on the Mount, he calls us (his disciples) the light of the world—the same as he.

As before, Jesus does not say, “Be light!” or “Get light.”  He says, “You are the light…”  We are what Jesus says simply by the power of his Word.  In the beginning, God said, “Let there be light,” and there was light.  Now Jesus says, “You are the light of the world,” and so we are.

And our light cannot be hidden.  Just as no place one earth can escape the sun’s rays, so also no Christian can cover up their light.  The Church is like a city on a hill that shines like a beacon in the darkness.  Perhaps you have seen photos taken by astronauts of the great cities of the world at night.  They glow with warmth and light.  They cannot be hidden.  Neither can we.

The local church, our gathered community of believers, is also a city on a hill—or at least a city across the street from a hill.  (I’m referring to the Santa Fe quarry butte across the road, which is actually an extinct volcano, if you didn’t know).  A light can only shine.  It can do nothing else.

So Jesus says, “In the same way, let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven” (Matt. 5:16).  What is the inevitable purpose and result of being salt and light?  The world will see our good works and give glory to God.  As Lutheran Christians, we believe what the Bible means when it says that we are not saved by our good works.  Romans 3:28: “For we hold that one is justified by faith apart from works of the law.”  “For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast” (Eph. 2:8-9).

Good works cannot save us, but that doesn’t mean that good works do not matter.  We are not antinomians.  We do not believe that God’s Law is bad.  As St. Paul writes, “Now we know that the law is good, if one uses it lawfully” (1 Tim. 1:18).  The Lutheran understanding of Law and Gospel does not mean Law versus Gospel.  It means simply that our good works cannot commend us to God.  We are saved by grace alone through faith alone in Christ alone.  He is the one who died for us, who blesses us, who declares us to be salt and light.  We can do nothing for ourselves.

Good works are not necessary for salvation, and yet the Bible tells us that good works are necessary.  In fact, God created us to do good works (Eph. 2:10).  But why?  “That they may see your good works and give glory to your Father who is in heaven” (Matt. 5:16b).  Martin Luther famously quipped, “God does not need my good works, but my neighbor does.”  God works through us to love and serve our neighbor.  As the children of God, we reflect the character of our heavenly Father through our words and actions.  So when we bless our neighbor by doing good works in love, they in turn will rejoice and glorify God.

But the glory is not ours.  It is for God, not for us.  As the Bible says, “So, whether you eat or drink, or whatever you do, do all to the glory of God” (1 Cor. 10:31).  “Not to us, O LORD, not to us, but to your name give glory…” (Ps. 115:1).  Disciples of Jesus do not want the glory.  The purpose of a light or lamp in a museum or old palace is not to attract attention to itself, but to illuminate the beautiful things worthy of our admiration.  We point people to Jesus.  Our light shines on him—and his cross.  “For I decided to know nothing among you except Jesus Christ and him crucified” (1 Cor. 2:2).  That is why our outreach campaign uses the slogan, “Shining the light of Christ in Castle Rock.”  We are the light of the world, so let your light shine before men!

“Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them.  For truly, I say to you, until heaven and earth pass away, not an iota, not a dot, will pass from the Law until all is accomplished” (Matt. 5:17).  Some Christians wrongly believe or teach that the Old Testament Law no longer matters now that Christ has come.  That was then, this is now.  Out with the old, and in with the new.  But that is a deadly dangerous teaching.  The heretic Marcion claimed that the Old Testament had no more relevance for Christians, and he read his Bible with a knife, cutting out any parts that he didn’t like.

But Jesus did not come to abolish the Law and the Prophets.  The Old Testament was God’s Word back then, and it remains God’s Word today.  The Ten Commandments did not become the Ten Suggestions simply because Jesus died and rose again.  God’s Law is still his will for creation.  It still serves as a mirror, a curb, and a guide for those who seek to live a godly life.  The Law gives shape to our love.  It tells us how to love God and how to love our neighbor.  “Love does no wrong to a neighbor; therefore love is the fulfilling of the law” (Rom. 13:10).

The trouble with the Law is that because of our old sinful nature, that continues to war against us, we continue to fall prey to temptation.  We still sin.  We all fall short of the glory of God.  And so we cannot save ourselves by obedience to the Law.  That is why Jesus came to fulfill the Law.  He kept the Law perfectly for us, so he became the perfect sacrifice for sin, and when he offered up his lifeblood on the cross, God accepted his offering on our behalf, because Jesus never sinned or did everything wrong.  He fulfilled every single requirement of the Old Testament Law, right down to being circumcised on the eighth day and appearing in the Temple on the fortieth day of his life.  That is why, on the cross, Jesus was able to declare, “It is finished!” (John 19:30).

“Therefore, whoever relaxes 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.  Unless your righteousness exceeds that of the scribes and Pharisees, you will never enter the kingdom of heaven” (Matt. 5:19-20).  The scribes and the Pharisees were seen as the spiritual rock stars of ancient Israel.  They were the ones who taught God’s Word to the regular, common people.  Most of the Jewish priests by Jesus’ day were corrupt and in the pocket of the Romans.  But the scribes and Pharisees still tried to do the right thing.  Unfortunately, they invented all kinds of human traditions not given in Scripture.  They went beyond Scripture, and in so doing, abandoned the Bible.  They became holier-than-thou hypocrites.  Yet by being self-righteous, they were not righteous at all, because no one can justify themselves.  If you try to be righteous, you remain unrighteous.

You can only be made righteous by another.  You must be declared righteous.  You must be justified—declared innocent and made right with God by judicial verdict.  The only way for your righteousness to surpass that of the scribes and Pharisees is if “your” righteousness is not your own.  It must come from outside of you (extra nos)—an alien righteousness.  “The righteous shall live by faith” (Rom. 1:17)—faith in Jesus Christ, the only sinless Son of God.  Only Jesus can make you righteous.  Only Jesus’ blood can wash away sin.  Only Jesus can satisfy those who hunger and thirst for righteousness (Matt. 5:6).  Jesus must give us his righteousness.  He is our righteousness, and he gives us himself.  He alone can make us salt and light.  Praise be to Christ!  In the name of the Father and of T the Son and of the Holy Spirit.  Amen.

[1] All Scripture references, unless otherwise indicated, are from The Holy Bible, English Standard Version.

[2] https://www.npr.org/sections/13.7/2014/11/08/362478685/from-salt-to-salary-linguists-take-a-page-from-science#:~:text=Being%20so%20valuable%2C%20soldiers%20in,as%20the%20word%20%22salary.%22