Matt. 5:4 "Blessed are those who mourn, for they shall be comforted.
When you read something like this it might seem like a contradiction at first, but since Jesus said it, it is no contradiction.
How can we be happy and mourn? What does mourning have to do with happiness?
As I said before, the Beatitudes are connected to each other and it is not hard to see this connection to the first, "Blessed are the poor in spirit". When we see ourselves for what we truly are, spiritual beggars having nothing, it is then that we can begin to mourn over our sin.
Without salvation we can have no true joy, and without conviction of sin, there is no repentance, and without repentance there is no salvation. So, after conviction and repentance comes salvation and then comes joy. One of the main problems with the church today is the lack of focus on sin. No one wants to hear the bad news, but if we don't hear the bad news, the good news is of little importance, because "we are fine".
Our chief example to follow is always Christ and as far as I can tell there is no place recorded in the Bible of Him laughing. He wept, John 11:35, He mourns and weeps over Jerusalem, Luke 19:41, He was a man of sorrows and acquainted with grief, Is. 53:3 and apparently He looked much older than He was, John 8:57. It is not popular today to be sorrowing, or mourning. We are often told to be joyful or happy all the time, but it seems that Jesus' example is very different than the way we are expected to be today.
"To 'mourn' is something that follows of necessity from being 'poor in spirit'. It is quite inevitable. As I confront God and His holiness, and contemplate the life that I am meant to live, I see myself, my utter helplessness and hopelessness. I discover my quality of spirit and that makes me mourn". L-J. This is where Paul was coming from in Romans 7. He saw his sin, and the hold it had on him, and this made him mourn.
We not only should be mourning over our own sin, but as Jesus already has shown us, He mourned over the sin of the people of Jerusalem. When we see the lifestyle of sin in others that is keeping them away from salvation and true joy, this should cause us to grieve for them.
The Bible is full of admonitions for us to be sober, vigilant, and temperate. There, again, is a noticeable lack of telling us to be laughing. In fact Jesus says, "Blessed are you who weep now, for you shall laugh later." Luke 6, the parallel passage to this one.
"Great sorrow leads to great joy and without sorrow there in no true joy." L.J. Much like there is no need for grace without sin, and God's glory is shown by His graciousness in dealing with our sin, which should bring us joy and Him praise. The same is true of our mourning over sin. When we see our sin and repent from it, we are then forgiven and the joy that comes from forgiveness is true joy.
So what does this man look like? "He is sorrowful but not morose. He is serious, but not solemn. He is grave, but never cold. There is with his gravity a warmth and attraction." "A true Christian is never a man who has to put on an appearance of seriousness or joviality. No, No; he is a man who looks at life seriously; he contemplates it spiritually, and he sees in it sin and its effects. He is a serious, sober-minded man. His outlook is always serious, but because of those views which he has, and his understanding of truth, he also has a 'joy unspeakable, full of glory'". L-J.
"The joy of the Christian is a holy joy, the happiness of the Christian is a serious happiness". L-J.
When we see our sin for what it is and we confess and repent, we have joy like David was looking forward to in Ps. 51. "make me to know joy and gladness, that the bones which have been broken may rejoice". "Brokenness and mourning" go together before joy comes.
Some struggle with the mourning part, some struggle with the joy part. This is our fallenness and we need God to give us a balance of mourning over our sin and joyful restoration.