"Mourning" as it is used here does not refer to just any kind of misery, but is referring to grieving due to sin (personal, social or global)
It is not the sorrow or mourning or bereavement that Jesus refers to, but the mourning and sorrow of repentance.
The world is light hearted about many serious issues that result from sin, but focus on many things that are temporal and seem important today. The world grieves over a broken heart, a lost job or a death, but ignores the violation of God's ways and rejects the savor who was sent to bring comfort.
Now is not always.
Psalm 119:136 refers to tears as a result of the failure to follow God's standards
Ezekiel 9:4 refers to people
who are mourning due to the evil and wicked practices occurring in the
Ezra 10:6 - Ezra weeps for
the sin the returning exiled committed when they quickly forsook God's Law upon
their return to
John the Baptist's preaching
Malachi 3:1-4 is similar
Weeping for sin is effective. It leads to repentance and change.
Mourning is productive but the following responses to sin will only lead to destruction:
Psalm 51:4 - David confessed sin
Daniel 9:19-20 - Daniel confessed sin
Romans 7:24 - Paul considered his sinful state to continually be a wretched state
1 Corinthians 5:2 - the people should have grieved over sin, not accepted it
2 Corinthians 12:21
Philippians 3:18 - said with tears that many reject Christ
The mourning for sin will be comforted by the Messiah when he comes.
"Comfort" is parakalew /parakaleo/ and means "encourage as in Heb. 3:13
Isaiah 40:1 - the Messiah's mission from God was to "Comfort, comfort my people"
Luke 2:25 there were people
waiting for the consolation of
Isaiah 61:1-4 addresses the first two Beatitudes including:
There is hope and joy for those who are comforted today by the Messiah
And, there is greater hope and joy for those He comforts in the future.
1 Thessalonians 4:13