The Psalmist declared that, "They that sow in tears shall reap in joy." This text from Matthew, the second verse in the Sermon on the Mount, ultimately points to what the coming of Christ has accomplished.
These words from Christ may appear contradictory to us. Those that spiritually and physically mourn don't feel blessed and certainly they would believe their comfort is in doubt. The words have a deep spiritual and theological significance however. The words primarily address those that recognize their need for salvation. Jesus is addressing those that understand their fragile state, the seriousness of sin, and what it means for their soul. They mourn over the seriousness of their sin and the despair and havoc it wreaks. There is indeed a blessing in these actions.
Today in our culture, public sin is less controversial, if it is noticed at all. Sin is glorified by the culture and one wouldn't be incorrect in saying we are living in a period not unlike the time of the Judges. The famous refrain from Judges of course was, "Everybody did what was right in their own eyes."
Those that mourn over their sin are being called out of themselves and are being configured and made into the image of Christ. How beautiful is the Lord to us when we realize the very God who we have sinned against is the God who has saved us. "Not with the proud -- not with you who think yourselves good and excellent -- does God dwell; but with men who feel their sin, and own it; with men who feel their unworthiness, and confess it," says Charles H. Spurgeon.
It's also hard to imagine that one would mourn over the sin and the lost state of others if they did not indeed mourn over their own sin. It is why the Apostle Paul, a holy man indeed, declared himself "the chief among sinners."
Likewise, because we are forgiven, it is important not to continually point out the shortcomings of others, or ourselves, but we should never minimize sin in our lives.
If we feel far from God, repentance is the best place to start. It was John the Baptist who announced the coming of Christ with the words, "Repent, for the Kingdom of Heaven is now close at hand." God is restoring all of creation and making it into His image. Don't let pride, conceit, or arrogance leave you behind. And when we do mourn our sins, we should be confident in knowing that because of the love of Christ, he has given us a precious peace through his blood.