In the Gospel according to Luke, Jesus Christ comes to announce the immediate arrival, in his person, of the Kingdom of God. The overriding theme of Jesus' life and ministry, the cause of his death, and the purpose of his resurrection is that the Kingdom is here, the era of the Spirit is inaugurated.
In displaying this Kingdom Jesus makes it clear that the invitations have already been sent. God, according to Jesus is making a wild offer of extravagant hospitality to any and all who accept. The principal question, left hanging by the writers of this Gospel, is whether or not we will join the celebration.
Note, that the celebration is already going on. Note, also, that none of the traditional obstacles to participation are present. People of every class and social status, of every tribe and nation, gender, and religion are invited and at various times shown to be participants in the feast. Furthermore, the Gospels go to great length to prove that not even sin is an obstacle to joining the party. The stance of Jesus toward sinners is one I would describe as "preemptive celebration".
Consider Zacchaeus, for example. Before Jesus ever even lays eyes on this vertically challenged thief, he announces to him that he will be coming over for dinner. Jesus doesn't confront him over his thuggery. Jesus doesn't give any hint that he has any purpose but procuring a full belly and a bed. Jesus definitely doesn't make his presence contingent on Zacchaeus' repenting. The party was going to happen regardless.
Jesus does this again and again. He eats with sinners. Not ex-sinners. Not repentant-sinners. He even makes a point of NOT washing his hands before dinner - making the point that coming to the meal unclean doesn't matter, it's being a generous host that matters. In other words, since the party is already rolling, the only thing that matters is deciding to attend.
There is the rub. When making the decision of whether or not to attend there IS one thing, and ONLY one thing that can get in our way - our own self-righteousness. It is the self-righteousness of the pharisees that keeps them from joining Jesus in dining with sinners - and it is this which he criticizes more harshly than anything else in the Gospel. It is ultimately, the point of the latter half of the parable of the prodigal son. The elder son excludes himself from the celebration even as the father comes and pleads with him to join. The parable ends without the question answered: will the elder son accept the invitation? The only thing stopping him is his own indignation.
Unfortunately elder sons and pharisees frequently find themselves in positions of worldly power and believe they have the ability to exclude certain undesirables from the ongoing feast. They do so by telling us that the true feast is in the future or in heaven instead of here and now. They also exclude by establishing standards - the most basic of which is repentance. They harass and cajole us into believing that God's offer is a starkly contingent one, we have to sign on the dotted line and show our identification before being admitted. They try their best to catch sinners headed to the feast and cause them to stumble. A practice for which Jesus had no patience. The tragedy is that they ultimately exclude only themselves from the joy of God's festival.
By contrast, Jesus kicked things off with a party. He celebrated before anything else. Before even making introductions in many cases, and certainly before anyone could try and formulate a guest list and start vetting the crowd for the event Jesus was attending. He celebrated preemptively. Cutting potential objections off with a burst of frivolity.
Our contemporary pharisees will call this antinomianism in an attempt to scare us back into line. They regarded Jesus as a blasphemer and a lawbreaker as well, but Jesus responded that his behavior was the very fulfillment of the law. What is the law but a tool to bring people to God? What does it mean to be in God's presence but to celebrate? In joining the celebration we are already fulfilling the law, whether we've come to the table with clean hands or dirty.
Furthermore, preemptive celebration doesn't circumvent repentance - it is perhaps the only ground upon which legitimate repentance is possible. Only by accepting the place already prepared for us at the table, can we accurately reflect on the grace which brought us there and be free from self-righteousness which is the one insurmountable obstacle to a penitential heart. Be like Jesus - practice preemptive celebration.