Matthew 5:21-37 (Sixth Sunday after the Epiphany—Series A)
“A Matter of the Heart”
Lutheran Church of Our Redeemer, Enfield CT
February 16, 2020
Grace, mercy, and peace to you from God our Father and from our Lord and Savior, Jesus Christ. Amen.
Our text is the Gospel recorded in Matthew 5:
21You have heard that it was said to the ancients, “You shall not murder, and whoever murders will be liable to the judgment.” 22But I myself say to you that anyone who is being angry with his brother will be liable to the judgment, and whoever says to his brother, “Numskull,” will be liable to the Sanhedrin, and whoever says, “Fool,” will be liable to the hell-fire. 23Therefore, if you are bringing your gift to the altar and there you remember that your brother has something against you, 24leave your gift there before the altar and go, first be reconciled to your brother, and then come and resume offering your gift. 25Be well-disposed toward your opponent quickly, while you are with him on the way, lest that opponent hand you over to the judge and the judge to the assistant and you will be thrown into prison. 26Truly I say to you, you will surely not get out from there until you pay the last cent. 27You have heard that it was said, “You shall not commit adultery.” 28But I myself say to you that anyone who looks at a woman so as to desire her has already committed adultery with her in his heart. 29And if your right eye causes you to stumble, tear it out and throw it away from you, for it better for you that one of your members perish and your whole body not be thrown into hell-fire. 30And if your right hand causes you to stumble, cut it off and throw it away from you. For it is better for you that one of your members perish and your whole body not depart into hell-fire. 31And it was said, “Whoever divorces his wife, let him give her a certificate of divorce.” 32But I myself say to you that everyone who divorces his wife, except for a matter of adultery, makes her to have adultery committed [against her], and whoever marries a divorced woman commits adultery. 33Again, you have heard that it was said to the ancients, “You shall not break your oath, but you shall pay to the Lord your oaths.” 34But I myself say to you not to swear at all, neither by heaven, because it is God’s throne, 35nor by the earth, because it is the footstool of his feet, nor by Jerusalem, because it is the city of the great King. 36Neither should you swear by your own head, because you are not able to make one hair white or black. 37But let your word be “yes, yes,” “no, no.” That which is more than this is from the evil one.
You have heard that it was said, “You shall not murder.” You reply, “I have never killed anyone.”
You have heard that it was said, “You shall not commit adultery.” Your response, “I have never cheated on my spouse.”
You have heard that it was said, “You shall not break your oath.” Your reply, “Well, I have broken some promises.”
Hey, you know the saying, “Two out of three ain’t bad!” Even one out of three is a .333 batting average in the big leagues, and that’s considered outstanding—1 hit out of every three times at bat! So keeping one commandment or, imagine, two commandments out of three has to be quite impressive to the Lord! We have heard that it was said do not murder, do not commit adultery, and do not break your oaths. And we look at the letter of the Law and say that we’ve done quite well. However, Jesus tells us, “You have heard that it was said . . . but I myself say to you . . .” Wait, what? There’s more to it?
Yes, there is. Much more, says Jesus, so that no one can read this text from the Sermon on the Mount without saying, “Ouch! It hurts!” Jesus reveals to us that “doing the commandments” is not simply about avoiding the actual deed. It is a matter of the heart and the condition of the heart. Not only is murder sinful, but so is hatred. Not only is adultery wrong, but so is lust. Perjury and lying is sinful, but so is breaking promises. Mere external conformity to the commandments is not enough. Jesus opens our minds and hearts to see that God also demands internal purity and righteousness as well.
Last Sunday, we left off in Jesus’ Sermon on the Mount with the words, “For I say to you that unless your righteousness exceeds that of the scribes and Pharisees, you shall surely not enter into the reign of heaven” (Matt. 5:20). The scribes and Pharisees of Jesus’ day were all about the outward performance—the deed itself. So if the commandment says Do Not Murder, they do not take someone’s life. But Jesus gets to the heart—literally—of His own commandments. It is more than the actual deed of murder or adultery or lying. It is also hating, lusting, breaking promises. It’s a matter of the heart.
Jesus would tell His disciples in Matthew 15, “For out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false witness, slander. These are what defile a person” (Matt. 15:19–20a ESV). The human heart, because of our inherited sinful nature, is crammed full of anger and hate, envy, hidden and evil schemes of murder, and lusts from which obscene language and vulgar gestures proceed. God’s word in Jeremiah summarizes for us: “The heart is deceitful above all things, and desperately sick” (Jer. 17:9 ESV). From our hearts to our minds to our mouths come curses, hate-filled words, lustful desires, and broken promises that hurt and harm our neighbor physically and emotionally, mentally and spiritually.
Jesus tells us that we must be more righteous than just an outward keeping of the Law. True righteousness must be in the heart. When the heart is pure, it will never produce selfish anger, insults, grudges, lust, divorce, and lies. So how well have we done with that?
Lousy!—because our hearts, by nature, are not pure! We can keep from killing or having affairs, but we can’t control all those little sins that pop out of the heart. The heart always slips—generates selfish thoughts, lets our tempers snap or harmful words slip out. And, hey, our eyes are open—temptation just jumps in! “Soon the heart follows the eyes, bringing on the desire and appetite that I ought to reserve for my wife alone. Flesh and blood is curious enough anyway. It soon has its fill and loses its taste for what it has, and it gapes at something else.”
But surely, we can’t be responsible for all these thoughts and desires and angers and jealousies! They just seem to happen on their own. But Jesus says we are responsible—“And if your right eye causes you to stumble, tear it out and throw it away from you, for it better for you that one of your members perish and your whole body not be thrown into hell-fire. And if your right hand causes you to stumble, cut it off and throw it away from you. For it is better for you that one of your members perish and your whole body not depart into hell-fire” (vv. 29–30)!
Now Jesus isn’t saying that we should literally blind or maim ourselves. He is saying, “Stop making excuses!” It’s not eyes or hands that make you sin. It’s the heart that causes sin. “Out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false witness, slander.” Even the smallest sin proves our hearts aren’t pure, and Jesus demands a pure heart—not a mere outward keeping of the commandments, but a truly pure-hear-keeping of the commandments. Our righteousness must exceed that of the scribes and Pharisees. So to be righteous, the heart has to be repaired. And where can we get that?
Christ Himself gives us pure hearts. It is the blood of Christ poured out for us on the cross that purifies every heart. Consider your physical heart. It’s a most valuable organ—provided there’s blood in the body to pump. The blood of Christ flowing through the spiritual heart makes our heart righteous. This the blood of Christ shed on the cross in His death for us in our place that was applied to you and me in the purifying effects of Baptism. So Baptism is a washing that renews and purifies us before God. Instead of the blood of lambs or goats, it is the blood of Jesus that cleanses us (Heb. 9:13-14). This is the same blood we receive in, with, and under the wine in Holy Communion for the forgiveness of sins, new life, salvation, and the strengthening of our faith in Christ as Lord and Savior.
The blood of Christ gives us His own righteousness that exceeds that of the scribes and Pharisees. It gives us a righteousness beyond the letter of the Law to the very “heart of the matter.” Sins—big outward ones and small ones in the heart—are all washed away. Jesus’ blood has truly paid for every murder and every harsh word, every affair and divorce and every look that was a little too long, every perjury, and every promise we broke. “The blood of Jesus . . . cleanses us from all sin” (1 John 1:7 ESV). Though our hearts are corrupt, God declares them righteous because of the sacrificial death of Jesus. In a very real way, then, Christ’s blood gets our spiritual hearts pumping. His blood makes us alive when we were dead in trespasses and sins. His blood gives us new life and eternal life as He sends the Holy Spirit to transform our hearts.
After his sins of lust and adultery, deceit and murder, David prayed in Psalm 51, “Create in me a clean heart, O God, and renew a right spirit within me” (Ps 51:10). David knew his sinfulness and the Spirit’s promise to change him. When we believe in Christ, a radical change does occur: the Holy Spirit creates a new heart, a new spirit in us. This new heart really is righteous and pure, even though it’s living alongside what remains of our old sinful one. But the Holy Spirit also lives in us so that our hearts are constantly communing with Him. God the Holy Spirit then enables our hearts to produce pure actions—the fruits of faith, good works, faith toward God and love toward neighbor.
Yes, our sinful nature continues to sin until the day of our death. But the new heart made righteous by the blood of Christ through the power and grace of the Holy Spirit does love our neighbor, honor our spouse, and treat others with honesty and integrity. You see, our righteousness before God is always a matter of the heart. And by Christ’s blood through the gift of His Spirit, Jesus has resolved that matter—in our hearts—with His forgiveness. 1 Corinthians 6:11, “But you were washed, you were sanctified, you were justified in the name of the Lord Jesus Christ and by the Spirit of our God.” In Baptism, God has spoken to us by name, claiming us, cleansing us, and putting the saving mark of the cross on our head and on our heart. Now by the blood of Jesus we are able “to live under [Christ] in His kingdom and serve Him in everlasting righteousness, innocence, and blessedness, just as He is risen from the dead, lives and reigns to all eternity” (Small Catechism: Second Article). Amen.
 Martin Luther, Luther’s Works, Vol. 21: The Sermon on the Mount and the Magnificat, ed. Jaroslav Jan Pelikan, Hilton C. Oswald, and Helmut T. Lehmann, vol. 21 (Saint Louis: Concordia Publishing House, 1999), 87.