Is Paul responsible for Christianity? If so, what influence did he have? Did Jesus come to save Jews only?
Obviously, the person who had the most influence on the direction of Christianity was Jesus Christ. One can argue for either Paul or Peter as the two humans who had the greatest influence on the direction Christianity took after the ministry of Jesus on earth was completed. I am convinced that God is in control and that the writings of Paul and Peter (and the other New Testament writers) are inspired by God.
For this reason, I believe that the influence Paul had on the direction Christianity took was principally determined by God’s influence on Paul. Nevertheless, God uses real people, with real personalities, strengths and flaws. For this reason, the personality and personal character and even opinions of Paul had at least some effect on the future direction of Christianity. One can imagine that Paul’s zeal to plant churches affected the missionary zeal of the church. We can imagine Paul’s very strong Jewishness, combined with his strong conviction that we are saved by grace, not by works of the law had an effect on the direction of Christianity, although I am completely convinced that these were characteristics of Jesus as well. One can argue that to some extent the future organization the church–the role assigned to deacons, elders and evangelists, for example–was influenced by Paul’s work, in addition to the inspiration of the Holy Spirit. It is difficult to separate the influence of God, of Jesus and of the Holy Spirit from the personal influence of Paul as an individual. This is very hard to measure, but we can say that, working through Paul, God did much to determine the course of Christianity, especially in Greece and the Northern Mediterranean area. Jesus did not come to save the Jews only.
There is an almost unlimited number of quotes from the ministry of Jesus to the effect that salvation was for the Gentiles as well. Acts 10 is the story of how God convinced the apostles of what Jesus had already taught them–that salvation is for the Gentiles too. Romans 8-10 record’s Paul teaching the Jews one more time that, whether they like it or not, God’s intention all along was to save the Gentiles. The entire book of Jonah is a historic parable about the fact that salvation is for the Gentiles too. Jonah was not too happy about this message. I will not bother to quote a lot of passages from Jesus telling the apostles that their ministry was to be to all people: not just for the Gentiles, but let Acts 1:8, Matthew 11:22 be a starter.