According to Paul, what was it exactly that most of the Jews had failed to grasp regarding the coming of Jesus?
TWH: In order to discuss what Paul thought, I think we need to back up and talk about what took place in the life and ministry of Jesus. The nation of Israel was presented with their Messiah. At every turn in the life and times of Jesus, he is presented and confirmed as the rightful heir to the Davidic throne. (For a little tangential thought, click here.) When we look at the Gospels, we need to see that one of their purposes is to show Jesus being presented as the Messiah. The Gospels show us this because it was an important element to Jesus' ministry! Of course, the Gospels concentrate primarily on the last week of Jesus' life. Each of them basically devote about forty percent of their content on the events taking place during that last week. Clearly the last week of Jesus' life is tantamount, primarily because the crucifixion and resurrection are central to the Christian faith. Let's take a look at (1) the ministry of John the Baptist and Jesus Christ, (2) the events of Matthew 12–13, and finally (3) Paul's argument about the Gospel and the identity of Jesus Christ.
First, let's take a look at the ministry of John the Baptist and Jesus. John is announcing the coming of the Messiah; he is not announcing himself. He continually points away from his ministry to a greater ministry that must overshadow his own. Even with John's message, the people are presented with a message calling for repentance and a return to covenant obedience with God. They are presented with a message that one is coming who is stronger than John, one who will baptize people with the Spirit of God. And they should prepare their hearts for him, so that when he appears on the scene they will be ready to embrace him as their Messiah.
Unfortunately, John's message was challenged by the religious elite. A great number of Israel's population were drawn out to the Jordan to hear this one crying out in the wilderness. But John's message was challenged. Being drawn out to hear a prophet like no one had heard at that time is not the same as embracing John's message or Jesus as the Messiah when he actually comes on the scene and starts his traveling ministry proclaiming the kingdom of God. The Jewish people failed to grasp the identity of Jesus Christ. The messages of John and Jesus were identical initially (Matt. 2:1; 4:17). The kingdom was being offered to the nation. But there was a covenant that governed God's interactions with the people. We know it as the Mosaic Covenant. John's message is preparatory. He says in essence, "Prepare your hearts now and repent, for the one we've been waiting for is almost here!" Jesus extends the same invitation to the people, only he shows them that the king is standing right before their very eyes. We all know what happens. The nation does not repent. The people were drawn out to listen to Jesus, as they had been with John (only to the nth degree). They wanted to listen to him, and they wanted to see him heal their loved ones and perform miracles. They were astonished by his teaching (e.g., Matt. 7:28-29). Some, no doubt, experienced the sort of repentance that both John and Jesus were calling for. Some were convicted of their sinfulness and asked God to be merciful to them. But despite the large crowds, the overwhelming majority of the people were hesitant to wholeheartedly give their allegiance and their obedience to this Jesus. That's why Matthew 12–13, to which we now turn our attention, are critical to understanding the Gospels and the ministry of Jesus Christ.
By the time we get to Matthew 12–13, Jesus has preached in the synagogues, on mountainsides, on the shores of Galilee. He's traveled right into Samaria to meet with a woman at a well. He's gone from one side of the Sea of Galilee to the other just to heal a demon-possessed man and set him in his right mind. He's told everyone to seek the kingdom of God first and, by default, to seek the king of that kingdom. He's given them the standard by which God judges whether or not someone is a covenant-keeping individual (e.g., Matthew 5–7). He's healed all sorts of infirmities. He's met with teachers of the Law like Nicodemus and explained what it means to be born again. He's trained up his closest disciples and he's sent them out to neighboring cities to proclaim the kingdom of God. He's been busy about his Father's business.
But what had Jesus not done? Well, for one, he had not overturned the Gentile government to which Israel was subjected. And everything the prophets had promised regarding a kingdom whose reach knew no end was not yet in effect. Israel's greatest prophet, according to Jesus himself, failed to grasp something about the Messiah. John sent at least two of his trainees to inquire whether or not Jesus was the one they had been waiting for, or whether they should look for someone else (Matt. 11:3).
So, why do I mention Matthew 12–13? The nation of Israel did not just fail to grasp something regarding the coming of Jesus. No, they actively rejected something . . . someone. What we are dealing with is not just a naïvety or hermeneutical misunderstanding. We have to realize that Jesus' world was completely at odds with the world of first-century Judaism, especially that of the religious elite. It's no wonder that John is so confrontational with the envoys sent from Jerusalem! Likewise Jesus with the all that the Pharisees and Sadducees stood for. Remember what Jesus said: "For I say to you that unless your righteousness surpasses that of the scribes and Pharisees, you will not enter the kingdom of heaven" (Matt. 5:20). But his frustration was not only directed towards the religious elite. No. Jesus condemned the cities in which most of his miracles were done because they had not repented (Matt. 11:20). The main issue was not that the nation failed to grasp something about Jesus so much as theirs was a spiritual problem in the lives of the Jewish people (as there is in all peoples).
Something happens in Matthew 12 that causes Jesus to shift gears in his ministry. Beginning in Matthew 13, Jesus begins to speak in parables. That there was such a major shift in his ministry is impossible to overlook, after all, even his closest disciples ask him why he starts teaching in such a way (Matt. 13:10). In Matt. 12:22-24, Jesus is officially rejected as the Messiah by the nation of Israel. He did not fit their expectations. And they did not meet Jesus' expectations. The two worlds were at odds. Nevertheless, Jesus is their Messiah. Whether they accept him or not, he is their Messiah. Because they attribute his miracles to Satan, some of them (how many?) are judged by Jesus and told that they have committed a sin that will not be forgiven. And Jesus would know whether or not they would be forgiven, since he is the one to whom all authority to judge has been given (John 5:22). What takes place as a result is there is a divine hardening (Isa. 6:9-10; Matt. 13:14-15) on the people's hearts for their unrepentant stance and their blatant rejection of Jesus by attributing his divine power to Satan. I don't think the issue is they failed to grasp who Jesus is. I think the issue is that they failed to repent after seeing who Jesus is.
So, what about the message Paul preached? Honestly, I can't see the basis for claiming that Paul remained a faithful Jew and only exempted Gentile converts from the burden of keeping the Law. That whole concept seems irreconcilable to the rest of the New Testament, especially Romans and Galatians. Romans is written to a mixed audience of Jews and Gentiles. And the first portion of the letter is dedicated to placing the Jews and Gentiles on level playing ground. "All" have fallen short. "All" have sinned. Sin entered the world and hit them all. Death spread to everyone. All have exchanged the truth of God for a lie. All have worshiped the creation instead of the creator. And all are under judgment. Paul says that the Jewish people received the law (Rom. 3:17-29), and they are condemned by it. And Paul says that the Gentiles have what God expects of them written on their hearts, and they are likewise condemned (Rom. 3:12-16). Everyone who commits iniquity, Paul says, will face tribulation and distress, "of the Jew first and also the Greek" (Rom. 3:9).
Once that leveling takes place so that Paul's audience knows that everyone has the same problem, he is able to explain to them God's solution for everyone under that curse. That's the gospel, specifically that God is demonstrating his love to us in the following way: While we were yet sinners, Christ died in our place on the cross as the sacrifice for our sins (Rom. 5:8). And faith is what gives people a right relationship with God. Faith in Christ is faith apart from any human merit. It is trusting entirely on God's mercy and Christ's sacrificial death on the cross. That right relationship with God comes to everyone, Jew and Gentile, only through believing in Jesus Christ, confessing with one's very life (not just their lips) that Jesus is Lord, and believing that God raised him from the dead (Rom. 10:9-10). The idea that Paul is giving one gospel to the Gentiles, remaining himself a fully devoted and unchanged Jew, while another gospel goes forth to the Jews cannot stand the test of the rest of the New Testament, not just Paul's writings.