This second Beatitude follows closely after the first—“Blessed are the poor in spirit…”—and has a vital connection to it. We will look first at the meaning of mourn and then later we will show why true mourners are blessed and comforted.

What did Jesus mean by mourn?

1. The kind of mourning Jesus meant here was a spiritual mourning, a mourning of our spirit and soul over sin. This mourning will follow being poor in spirit as we see our helplessness and hopelessness without God.
2. This mourning is a groaning within ourselves over the spiritual condition of the world, and over all sin and all trouble in the world (Rom. 8:32). And as the world says, forget your troubles, Jesus says, face your troubles and mourn over them and pray for blessing to come.
3. Mourning must begin first with ourselves over our own sins. At the end of each day it is good to recall all our thoughts and feelings and sins, and mourn over them in prayer.
4. We should mourn also over the sins of others and over all the problems in the world. Yes, be concerned and pray over your society and over the world as Jesus did.

When we mourn we can expect blessing and comfort from the Father.

1. The one who mourns is repenting for his own sins, and he is obedient in prayer over the sins of others. He repents and is obedient because the Holy Spirit is at work on him. And then soon, while in a prayerful mourning state, the Holy Spirit will comfort him and make him happy.
2. As D. Martyn Lloyd-Jones points out, “But there is not only this immediate comfort offered to the Christian. There is another comfort…” It is the comfort of the blessed hope, which is the hope we have in our redemption. This redemption, as we know, will come to us immediately when we see Jesus and are changed to be like Him. So as we mourn over our sinful state, we can be comforted in our future hope. And we should comfort one another with this hope (1 Thess. 4:18).