Blessed are the mourners
Understanding the sayings of Jesus presents a mighty challenge. What, really, was He talking about when He spoke of putting new wine into old wineskins, for instance? A perusal of a number of commentaries shows anything but a unanimity of opinion as to its meaning. Evidently we need to apply considerable thought to Jesus' words. Furthermore, dogmatism would be unwise. With these words of preamble let us consider the content of the virtue Jesus was referring to when He spoke of those who mourn (Matt. 5:4).
Strangely, general agreement seems to be the name of the game when it comes to this blessing. Boice says it refers to "mourning for sin" (The Gospel of Matthew), and John Stott declares, "It is not the sorrow of bereavement to which Christ refers, but the sorrow of repentance" ("The Message of the Sermon on the Mount"). While remembering his own caution against dogmatism, this author suggests that this interpretation does not fit as snugly as another interpretation does with a fundamental aspect of the beatitude blessings - they appear to look forward to and await fulfillment in the resurrection to eternal life. True, it can be argued that "being shown mercy" (vs. 7), for instance, applies to believers now; they do not have to wait until being received into Jesus' presence to know divine mercy. Nevertheless, a few of the promises plainly and exclusively apply to our future inheritance of the kingdom of God. "Inheriting the land" (vs. 5) and "seeing God" (vs. 8) are kingdom blessings, not this-life blessings. Unless one is willing to see in these blessings a mix of this-life and that-life promises of joy, one can conclude that all the blessings refer to the "joy set before us" (Heb. 12:2) in the kingdom of God. The "mercy" we will "be shown" in the kingdom of God is of a different kind than the mercy we receive now. "Being filled" in the kingdom of God (vs. 6) likewise sets before us a hope that we do not yet know. Similarly, "possessing" the kingdom of God (vss. 3 & 10) here would seem to make more sense if taken to refer to the believer's ultimate inheritance of the kingdom as distinct from already being its citizens.
Though this interpretation cannot be shown to be technically superior (that is, provable by recourse to specific words) to those interpretations which see promise of blessings in this life, the reverse is also true. But in the overall context of
the entire New Testament, which emphasizes over and over the ultimate blessings of godliness as distinct from the immediate blessings, this author proposes that the promise of comfort for those that mourn is referring to future comfort - comfort of the kind that Lazarus enjoys in the parable (Luke 16:26).
Building on this premise, the mourning spoken of is most unlikely to be referring to the sorrow of repentance. If there is any one blessing the Christian has almost in full in this life it is victory over sin and the joy that comes from knowledge of that victory. The blood of Jesus Christ makes believers as pure as the driven snow in God's eyes, as taught by the doctrine of justification. All our trespasses have been forgiven, and we have been "made alive together with Him" (Col. 2:12). Justified believers must continue to repent of sin (1 John 1:9) but they do not need to mourn about their status any longer, as those born again "cannot [practice] sin" (1 John 3:9).
Believers have lots to mourn about, however. Leon Morris probably comes very close to Jesus' meaning when he says that, "… it is those who mourn in the face of the evils that are part and parcel of life as we know it, those who mourn over the way God's cause is so often neglected. who are the truly blessed one" (The Gospel According to Matthew). Do we not grieve over the injustices in the world? Surely those who love their fellow man cannot help but feel near despair over the plight of millions of oppressed, brutalized fellows. They mourn that mankind cares nothing about God, that they are, at this moment, deprived of living in a world where the knowledge of God's glory stands as the goal and the underpinning of the world's educational system (Hab. 2:14); they will be comforted when they see Habakkuk's glorious prophecy fulfilled. Above all, a believer who walks in Jesus' company and hears His words as he reads the gospels will surely mourn that Jesus has been taken from him. We have lost our nearest and dearest loved one; He has gone, taken to heaven. We do not see Him as the disciples did. We cannot talk with Him face to face as His followers could. Believers fast to express their grief over His departure (Matt. 9:15). But, joy of joys, they will be comforted; they will be received into His presence and get to walk and talk with Him without hindrance (John 14:3). What more could one ask for?