“Blessed are those who mourn, for they shall be comforted. (Matthew 5:4 ESV)
In life we mourn over bad events or circumstances such as death, mistakes, disasters and etc, mourning about all these predicaments amounts to nothing but the only mourning that truly amount to something is spiritual mourning (i.e. those that grief about their sins). We can see Jesus talks about people who mourn are being blessed which is opposite to the world’s view about those who mourn. The theme of this blessings in the beatitudes are focused on spiritual blessings. Another word used for “blessed” as well is “happy”.
Jesus in this beatitude is talking about those who grief about their sins, they are the one that are being comforted. This mourning or guilt leads us to the gracious and merciful throne of God to humbly seek for repentance and forgiveness for our sins in all contrition of the heart and brokenness of the spirit. By this we receive comfort from God through the Holy Spirit.
This type of mourning leads us and keeps us on the path of eternity. If one do not feel guilty or mourn about their sins then that person needs to check the authenticity of his or her Christianity.
Jesus also reminds us as His disciples we will face persecution just as He did. We will be afflicted for His sake but in all thing we will receive comfort from God through the Holy Spirit.
True children of God mourn over their sins because they hate sin as their father in heaven hates sin because He is holy unlike the children of devil who loves or rejoice over wrong doing because the devil loves sin.
Brethren, it is a blessing for us to mourn over our sins because it leads and keep us in the path of righteousness.