Paul's teachings on justification are often pitted against Jesus' teachings of the kingdom. This does an injustice to Paul's writings. Paul directly mentions the kingdom fourteen times, but for some that is not substantial enough. Along with the direct references, the kingdom is alluded to through other imagery. When Paul mentions "Christ", he is indirectly referencing the kingdom. Jesus, in being called the Christ, is being proclaimed the messiah and ruler of the Old Testament kingdom of Israel. He is the ruler who will reign forever. So Paul might not mention "kingdom" explicitly enough for the Paulinites, but why should he? He is writing to churches filled with people already in the kingdom who should be able to pick up the kingdom imagery, especially after having been taught the Gospels. Paul's letters were not written to tell people who Jesus was; they were written to specific churches for specific purposes.
McKnight makes this debate between the teachings of Jesus and Paul more complicated than it needs to be. Although he is not alone in that. He attempts to reconcile John Piper's view of justification against N.T. Wright's view, of whom he does not mention. These two have been going at it for a while now. In 2007, Piper wrote an entire book directly attacking the thoughts of N.T. Wright: The Future of Justification: A Response to N. T. Wright. Wright responded in 2009 with Justification: God's Plan & Paul's Vision.
Paul's and Jesus' teachings don't have to be at odds with one another. How do we enter the kingdom? Through justification. What is the purpose of justification? To bring about God's kingdom here on earth. They don't conflict. You cannot have one without the other. Nor do we have to shoehorn justification into kingdom theology; it naturally fits. But we must be careful, because Jesus' teachings of the kingdom do not easily fit into an individualized justification theology.
The more I have been reading and teaching Paul writings, the more I am falling in love with them. His writings do not conflict with the good news of the kingdom; they elaborate how to live out the life one should live as a citizen of the kingdom. The problem with most teaching on Paul occurs when people take a single verse or section and go nuts on it rather than take the whole book and focus on its larger point.
Even in Galatians, one of the Paul's books on justification, he wrote that people who live by the flesh will not inherit the kingdom of God. (Galatians 5:21).
1 Corinthians 15, the section that McKnight references in his article as Paul's gospel, does mention the "kingdom" in 15:24. McKnight just stopped his discussion of Paul's teaching of the gospel before getting there. I guess Paul is expected to be concise.
It appears that Paul wrote his letters to the Galatians and the Romans to explain justification. Justification is not a thought that pervades his other letters. It baffles me why having a few letters explaining justification somehow pits Paul against Jesus. There should be nothing wrong with explaining how we are justified. That's good to know, but that does not counteract all of the teachings of Jesus on the kingdom.
McKnight chose to go to Paul's definition of the gospel, but I prefer to start with Jesus' gospel. The good news, according to Jesus, was the kingdom. It seems simple. I guess I might just oversimplify it. But the purpose of our justification is to be the kingdom.
N.T. Wright wrote in Justification: God's Plan & Paul's Vision:
Yes, say the scoffers, ethnic divisions are broken down, we know that, but why make such a fuss about it? The answer is that the church, thus united through the grace of God in the death of Jesus, is the sign to the principalities and powers that their time is up. Ephesians is not about the ordering of the church by the gospel for its own sake. "Ecclesiology" may sound secondary and irrelevant to some ardent enthusiasts for the old perspective, but that could just be because they are unwilling to face the consequences of Paul's ecclesiology. For him, the church is constituted, and lives its life in public, in such a way as to confront the rulers of the world with the news that there is "another king named Jesus" (Acts 17:7). Paul says it again: this was the grace given to me, this was the mystery revealed which I became a servant, the mystery lodged since all eternity in the creator's single plan: "that now the many-splendored wisdom of God might be made known to the rulers and authorities in the heavenly places, through the church, according to the eternal purpose which he has accomplished int he Messiah, Jesus our Lord" (Ephesians 3:10-11). How can "ecclesiology" be a secondary topic, unworthy to be associated with the great doctrine of justification, when Scripture itself gives this high a place? Why should not the point of justification itself be precisely this, that, in constituting the church as the single family who are a sign to the powers that Jesus is Lord and the they are not, it servers directly the mission of the kingdom of God in the world? It cannot be, can it, that part of the old perspective's reaction to the new is the tacit sense that once we associate ecclesiology with the very center of the gospel we will have to go all the way and rethink the political role and task of the church? Surely the wonderful "objective" scholarship of so many old perspective exponents would not allow such a motive to affect exegesis! And yet: Luther's "two kingdoms" theology may have more bearing on this than we might like to think. Not to mention the deep resistance, in some of the same circles where the old perspective still flourishes, to any attempt to articulate a gospel-based "kingdom" theology to complement and illuminate Paul's soteriology." (173-174)Wright went on:
There seems to be something about the joining together of resurrection and justification which some of our Western traditions have failed to grasp. Justification is more than simply the remitting and forgiving of sins, vital and wonderful though that is. It is the declaration that those who believe in Jesus are part of the resurrection-based single family of the one Creator God. Any preaching of justification which focuses solely or even mainly on Jesus' death and its results is only doing half the job. Justification is not just about "how I get my sins forgiven." It is about how God creates, in the Messiah Jesus and in the power of his Spirit, a single family, celebrating their once-for-all forgiveness and their assured "no condemnation" in Christ, through whom his purposes can now be extended into the wider world. All this, of course, might have been clear from a reading of the Gospels, but, alas, the same Western tradition that has highlighted the cross at the expense of Paul's full theology of resurrection has also highlighted a supposed Pauline soteriology at the expense of the Gospels' theology of the kingdom of God." (248)