“Blessed are those who mourn for they shall be comforted” (Matt 5:4). Christ said this as part of the Beatitudes (Matt 5:3-10)—eight attitudes/actions that will be in the lives of those who are truly part of the Kingdom of Heaven. They are the poor in spirit, the meek, the ones who hunger and thirst for righteousness, the merciful, the pure in heart, the peacemakers, and the ones who are persecuted for righteousness sake. If these are not in our lives, Christ says, “We are not part of his kingdom.”
Mourning is especially interesting. What type of mourning is he referring to? He is referring to mourning over sin. Those who are part of the Kingdom of Heaven (and yet live on this earth) live in bodies that are prone to sin, though they hunger for righteousness. They also live in societies that laugh at sin, promote it, and celebrate it. Therefore, those who are part of the Kingdom of Heaven will be in a constant state of mourning. Why? Because their bodies, don’t reflect their heavenly abode, and their societies are far from the law of heaven as well.
But why are these mourners “Blessed.” This word can be translated “Happy.” Happy are those who mourn. They are happy in the midst of their mourning over sin because this body (2 Cor 5:2) and this world are not their home (John 17:14). They are happy because they look like their Savior (John 8:31), the one whose teachings they follow and who also mourns (cf. John 19:41, 11:35). They are happy because one day their Savior is coming (Phil 3:20-21), and they will have new bodies, no longer fraught with sin. But also one day they will be part of a world where their Savior rules absolutely. His laws will be obeyed and followed throughout society (Ps 2:8-12). They are happy because their Savior is the ultimate rule, and he is coming soon—he will not tarry. Lord, come, Lord, come! Your people cry out and wait! Lord, strengthen your mourners in this hour! We wait for you!