The Second Beatitude
Blessed are those who mourn,
for they shall be comforted.
A person who mourns recognizes that they are a sinner before God. Such a person mourns over their sins because they recognize that their sin greatly hurts God. They also realize that they are without righteousness and do not even begin to deserve salvation and the joys of heaven. This miserable, but repentant sinner, realizes that only through the grace of God do they have forgiveness and salvation. Jesus says such a person is blessed. Those who are blessed in this way by God will see God and dwell with him forever.
What is the promise to those who mourn? They will be comforted. Who will be comforted? Only those who mourn, meaning only those who repent. Only those who grieve over their sins under the conviction of the Holy Spirit and cry out to God, saying, "I am a sinner" and ask for forgiveness. They will be the ones who will be comforted. Why will only these people be comforted? Because they alone know that Jesus Christ came to save the lost. They alone look to the cross of Jesus Christ and realize that Christ died for their sins.