Text: Matthew 5:4
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“Blessed are those who mourn, for they shall be comforted” (Matt. 5:4).
One of These People Is Not Like the Others
When I was a kid I watched Sesame Street, and one of the segments on the show was “One of these things is not like the others.”
In the Sermon on the Mount, Jesus says that the people of God’s kingdom should not be like other people. We should be different.
Jesus begins the Sermon on the Mount with the beatitudes. The second beatitude says, “Blessed are those who mourn, for they shall be comforted” (Matt. 5:4). When Jesus said these words, he was probably thinking of Isaiah 61:1-4.
Happy Are the Sad?
A few months ago, my wife and I met with a guy at the bank to take care of some financial matters. During our meeting, he talked about life insurance. And every time he mentioned a scenario in which Marsha or I died, he would say, “Heaven forbid.” Every time. People try to avoid thinking and talking about sad things.
How can Jesus say, “Blessed are those who mourn”? In essence, Jesus is saying, “Happy are the sad.” How do Jesus’ words make sense?
Charles Quarles explains the connection between Isaiah 61 and the second beatitude:
The context of Isaiah 61 portrays the “mourning” as an expression of sorrow over Israel’s exile, which was a punishment for their sinful rebellion. This mourning was thus an expression of grief from those suffering the consequences of sin and constituted an attitude of repentance. The appeal to Isaiah 61 in the second beatitude thus implies that the mourning of which Jesus spoke was mourning for sin and its grievous consequences. So when Jesus said, “Blessed are those who mourn,” he wasn’t talking about bereavement (i.e., sorrow over the loss of a loved one); he was talking about repentance (i.e., sorrow over sin). Repentance is a good kind of grief.
Citizens of God’s kingdom grieve over sin.
There is a connection between the first and second beatitudes:
The first Beatitude, “Blessed are the poor in spirit,” is primarily intellectual (those who understand that they are spiritual beggars are blessed); the second Beatitude, “Blessed are those who mourn,” is its emotional counterpart. It naturally follows that when we see ourselves for what we are, our emotions will be stirred to mourning. In Luke’s Gospel, Jesus says, “Blessed are you who weep now, for you shall laugh” (6:21). Later, he declares, “Woe to you who laugh now, for you shall mourn and weep” (6:25). “Woe” is the opposite of “blessed.”
True repentance is not merely being sad about the consequences of our sin; it’s being sad about sin itself. Often when a murderer is pronounced guilt of the crime, he will cry because of how the crime has affected himself, not because of the awfulness of his sin. The apostle Paul writes, “Godly grief produces a repentance that leads to salvation without regret, whereas worldly grief produces death” (2 Cor. 7:10). “True repentance makes no excuses and offers no rationalizations. It grieves for sin from a broken heart.” 
What Causes Us to Mourn over Our Sin?
What should cause us to mourn over our sin? The gospel. When we understand that God loves us and that Christ died for us, we should never enjoy sin. “The law of God convicts us of our sin…. But it is the grace of God that melts our hearts and causes a right attitude toward that sin, in sorrow, shame, and mourning.” 
Comfort Is Coming
Jesus promises that those who mourn over their sin “shall be comforted.” Those who repent of their sin will be comforted in two ways.
1. Those who mourn over there sin will be forgiven.
The parable of the prodigal son helps us understand God’s forgiveness.
“But when he came to himself, he said, ‘How many of my father’s hired servants have more than enough bread, but I perish here with hunger! I will arise and go to my father, and I will say to him, “Father, I have sinned against heaven and before you. I am no longer worthy to be called your son. Treat me as one of your hired servants”.’ And he arose and came to him father. But while he was still a long way off, his father saw him and felt compassion, and ran and embraced him and kissed him. And the son said to him, ‘Father, I have sinned against heaven and before you. I am no longer worthy to be called your son’. But the father said to his servants, ‘Bring quickly the best robe, and put it on him, and put a ring on his hand, and shoes on his feet. And bring the fattened calf and kill it, and let us eat and celebrate. For this my son was dead, and is alive again; he was lost, and is found.’ And they began to celebrate” (Luke 18:17-24).The story teaches that God’s forgiveness isn’t reluctant; it’s extravagant. It not only gives us joy; it gives God joy.
2. Those who mourn over their sin will one day be freed from mourning.
Sin is an ongoing struggle. Paul experienced this struggle: “Wretched man that I am! Who will deliver me from this body of death?” (Rom. 7:24). But one day this struggle will end. “[God] will wipe away every tear from [our] eyes” (Rev. 21:4).
Bad News and Good News
Sometimes a person comes to us with both good and bad news, and they say, “What do you want to hear first, the good news or the bad news?” The Bible gives us the bad news first: we are sinners in need of forgiveness. D. Martyn Lloyd-Jones writes that “conviction must of necessity precede conversion, a real sense of sin must come before there can be a true joy of salvation.” 
Once we acknowledge the bad news about ourselves, we can then receive the good news of the gospel: there is forgiveness through the blood of Jesus.
 Charles L. Quarles, Sermon on the Mount, Kindle locations 1199-1202.
 R. Kent Hughes, The Sermon on the Mount, 26.
 Quarles, Kindle locations 1215-1216.
 Sinclair B. Ferguson, The Sermon on the Mount, 19.
 D. Martyn Lloyd-Jones, Studies in the Sermon on the Mount, 45.