What is “Pauline Christianity?”

Answer:

You will always find people and groups who wish to cast doubt on sections of the Bible simply because they cannot accept what that section of the Bible teaches. For example, Martin Luther felt that the Book of James didn't really belong in the Bible. While he didn't go so far as to say it wasn't canonical, he didn't think it deserved to be studied.

"Therefore St James’ epistle is really an epistle of straw, compared to these others, for it has nothing of the nature of the Gospel about it."
[Luther’s Works 35, 362].

"The epistle of James gives us much trouble, for the Papists embrace it alone and leave out all the rest … Accordingly, if they will not admit my interpretations, then I shall make rubble also of it. I almost feel like throwing Jimmy into the stove, as the priest in Kalenberg did."
[Luther’s Works 34, 317].

"We should throw the epistle of James out of this school, for it doesn’t amount to much. It contains not a syllable about Christ. Not once does it mention Christ, except at the beginning. I maintain that some Jew wrote it who probably heard about Christian people but never encountered any. Since he heard that Christians place great weight on faith in Christ, he thought, ‘Wait a moment! I’ll oppose them and urge works alone.’ This he did."
[Luther’s Works 54, 424].

Luther's opposition to James simply comes down to the fact that James 2:14ff clearly shows that Luther was wrong in seeing faith and works being opposites.

The Messianic Jews really don't like Paul's clear teachings that the Old Law has been replaced with the Law of Christ. They want to claim that there are two sets of rules, one for the Jews and another for the Gentiles. Thus, many among the Messianic Jews strongly insist that Paul's writings are not inspired and don't belong in the New Testament. Others compromise and try to twist Paul's statements into something they find acceptable.

"Paul's teachings about Yeshua were very different from those of James, Peter, and the others in the Jerusalem group. It is striking that Paul's letters never quote Yeshua, rarely refer to Yeshua's teachings, and never mention Yeshua's life. Paul taught his own version of Yeshua's teachings and created his own rules. The Christian Church throughout the 2,000 years since Yeshua has been formed by Paul's teachings, not the teachings of James, the brother of Yeshua, and, some say, not the teachings of Yeshua himself."
["2000 Years of Pauline Christianity," Yeshua Before 30 C.E., 2006].

But Paul states that his writings come from the Holy Spirit who revealed the mind of God. "Now we have received, not the spirit of the world, but the Spirit who is from God, so that we may know the things freely given to us by God, which things we also speak, not in words taught by human wisdom, but in those taught by the Spirit, combining spiritual thoughts with spiritual words" (I Corinthians 2:12-13). When speaking boldly about an issue that he knew would be controversial, Paul said, "If anyone thinks he is a prophet or spiritual, let him recognize that the things which I write to you are the Lord's commandment. But if anyone does not recognize this, he is not recognized" (I Corinthians 14:37-38). Paul did not believe that what he wrote differed from what Jesus wanted to be taught. "Be imitators of me, just as I also am of Christ. Now I praise you because you remember me in everything and hold firmly to the traditions, just as I delivered them to you" (I Corinthians 11:1-2).

However, we also have the testimony of Luke, who wrote Acts, that Paul was selected by Jesus. "But the Lord said to him, 'Go, for he is a chosen instrument of Mine, to bear My name before the Gentiles and kings and the sons of Israel; for I will show him how much he must suffer for My name's sake'" (Acts 9:15-16). And Peter also testifies that Paul's writings are a part of the Scriptures (the writings of God). "And regard the patience of our Lord as salvation; just as also our beloved brother Paul, according to the wisdom given him, wrote to you, as also in all his letters, speaking in them of these things, in which are some things hard to understand, which the untaught and unstable distort, as they do also the rest of the Scriptures, to their own destruction" (II Peter 3:15-16).

Paul, Peter, John, James, and Jude did not have different visions about what Christianity should be like. They all taught the same message given to them by the same Spirit. The idea of a "Pauline Christianity" is a myth circulated by disgruntled false teachers.