Blessings and Woes
Why do we get this list of blessings and woes here, just as Jesus is setting out the essence of his teachings here (and in Matthew)? Well... Jesus is taking on the role of Moses as depicted in Deuteronomy, addressing Israel as the people prepare to enter/re-enter the Promised Land.
There is a Covenant announced, a deal with God-- and for God, there are enforcement clauses. Moses is portrayed offering blessings the people will enjoy in their new land, if and only if they fulfill their part. If they do not, those blessings are reversed and become curses.
Israel has been occupying the land for centuries, since Moses, but as the prophets warned, and most of Jesus' hearers agree, they have long suffered exile because their fathers broke the contract and came under its penalties.
Jesus is announcing 'the Kingdom of God', the chance to live in Israel under God's restored rule and favor.
But as before, there are conditions, including the chance to choose life, and blessings, or to remain under the curses of disobedience, to die in “the wrath to come” that John had spoken of. As NT Wright has eloquently, compellingly, and exhaustively argued, this 'wrath' is not 'the end of the space-time universe'; it is the same kind of calamity that earlier prophets had warned of, when it was Babylon that would punish Israel by conquest and exile.
In Jesus' warnings, the hovering threat is the overwhelming force and brutality of Rome crushing a nation of rebellious subjects. Some forty years later, Rome will kill and enslave multitudes in Judea, destroy the Temple, forbid Jews to visit Jerusalem, a shaking of the prevailing Jewish religious cosmos that only “apocalyptic” language could possibly express.
Despite the reference to "a rich reward in Heaven," Jesus is not telling individuals how to receive a pleasant afterlife. Like previous prophets, he is warning the nation and its rulers of oncoming doom, and what must be done to stave it off. He knows that his message will be equally unwelcome, that he and others will suffer and risk death in proclaiming it.
Unlike the Deutronomic Moses, addressing an Israel whom he knows will prove incapable of fulfilling God's demands, Jesus is offering the Kingdom to two Israels, one made up of people “with ears to hear”-- and the Israel of the Herodians, the High Priesthood, everyone who's been doing well under the present regime.
The poor can accept this covenant, and do it; the rich are content with their present condition, and will not.
Those who have been going hungry can accept, and will be fed; but those who have been content to leave their neighbors hungry... will remain content while their opportunity lapses.
Those who weep at the present state of things... will know a better; but those who can laugh in such times will find little to amuse them when the karmic bill comes due.
It is unlikely that this was a single sermon, given to all on one occasion. It would have been the message that Jesus spoke everywhere, differing slightly from one audience to another. Matthew's version is softened and abstracted in some details (the reference to “poor 'in spirit'” for example) but carrying the same message.
Wright explains the beatitudes well:
“Israel longs for YHWH's kingdom to come. She is ready to work and struggle and fight to bring it in. But the people to whom it belongs are the poor in spirit... YHWH has in mind to give her, not the consolation of an national revival, in which her old wounds will be healed by inflicting them on others, but the consolation awaiting those in genuine grief. Israel desires to inherit the Earth; she must do it in Jesus' way, by meekness. Israel thirsts for justice; but the justice she is offered does not come by way of battles against physical enemies. It is not the way of anger, of a 'justice' that really means 'vengeance'. It is the way of humility and gentleness. Israel longs for mercy, not least the eschatological mercy of final rescue from her enemies. But mercy is resolved for the merciful, not the vengeful. Israel longs for the vision of her God; but this is the prerogative not of those who impose an external purity, but of those with purity of heart. Isreal desires to be called the Creator's son, being vindicated by him in the dramatic historical proof of national victory. But those whom Israel's God will vindicate as his sons will be those who copy their Father, and that means peacemakers. Persecution will be inevitable for people who follow this way, Jesus' way, but those who are persecuted because they follow this way are indeed assured of a great vindication. In other words, the promise that would formerly apply to those who were faithful to Torah now applies to those who are faithful to Jesus [and his message.] Whatever they have meant to subsequent hearers or readers... the beatitudes can be read, in some such way, as an appeal to Jesus' hearers to discover their true vocation as the... people of YHWH, and to do so by following the praxis he was marking out for them, rather than the way of other would-be leaders of the time.”