In Galatians 1:11-12 the apostle Paul writes,
For I make known to you, brothers, that the gospel preached by me is not according to man. For I neither received it from man, nor was I taught (it), but (I received it) through a revelation of Jesus Christ.
Notice that Paul seems to be implying that a gospel received “from man,” at second-hand, is inferior to a direct revelation from Jesus Christ. And that idea seems to be consistent with Galatians 1:15-20, in which Paul goes on to write,
But when it pleased God—the one who separated me from my mother’s womb and who called me through his grace—to reveal his Son in me so that I might announce the good news about him among the Gentiles, I did not immediately confer with flesh and blood, nor did I go up to Jerusalem to the apostles (who were apostles) before me, but I went off into Arabia, and again returned to Damascus. Then, after three years [!], I went up to Jerusalem to become personally acquainted with Cephas [i.e., “Peter”; see John 1:42], and I stayed with him for fifteen days. But I saw none of the other apostles except James, the brother of the Lord [which is almost certainly a kind of metaphorical “title,” not the literal description of a biological relation; cf. John 20:17, Philemon 1:1, and Galatians 1:11, quoted just above]. And take heed, (in) the things I write to you, (I swear) before God, I do not lie.
Notice that Paul is saying all this as if it gave added credibility to his claim of having received a revelation from Jesus Christ, and to the content of that revelation. He apparently didn’t want people to think that he was just passing along second-hand “revelation stories” that he had heard from others. Moreover, it seems that Paul didn’t feel that he had much to learn from the other apostles, since anything he learned from them would have been merely “according to man.” He had already had his own personal, direct revelation—just as the other apostles had had theirs. (In fact, I think it’s reasonable to surmise that having had a personal, direct revelation from “Jesus Christ” is what was considered to make an “apostle” an apostle.)
As far as I am concerned, this passage provides virtually irrefutable proof that Paul did not regard “Jesus Christ” as an actual, historical, flesh-and-blood individual. Note that Paul makes a point of saying that after Jesus was revealed to him, he did not go to see any of the other apostles in Jerusalem. Instead, he waited three years before going to see them. If Paul understood Jesus to be an historical individual, one whom Paul now believed to be the one and only eternal Son of God, wouldn’t he have made it his absolute top priority in life to go as quickly as possible to the disciples/apostles who personally knew Jesus and spent time with him, so that he could learn everything that he possibly could about Jesus’s life and teachings from those who had witnessed everything first-hand? Wasn’t Paul concerned that some of them might die or forget some important things during that lengthy period of three years? Not all that much, it seems.
A Christian may be inclined to suggest that Paul, as a result of his personal revelation from Jesus Christ, must have already learned everything about Jesus Christ and his teachings that was possibly worth knowing. But how could he have known that to be true without first having spoken with the other apostles to find out what exactly Jesus had taught them, and what they had personally witnessed of his life, death, and resurrection? I would also ask that same Christian why, according to the traditional Christian account, God bothered to reveal himself in the flesh at all—if that is indeed an inferior and unnecessary way of going about revealing himself to human beings. Why didn’t God just reveal himself directly to all of the apostles in the form of “visions”? Well, I’m arguing that—at least according to how Paul saw things—that’s exactly what God did.
Galatians 1:15-20 shows that whatever exactly Paul understood “Jesus Christ” to mean—and it is admittedly evident that some notion of “Jesus Christ” did have great significance for Paul—it is not even conceivable to the mind of a reasonable person that Paul understood him to be an historical, flesh-and-blood individual.