It is true he only quotes Jesus directly once. However, Paul often quotes or paraphrases ideas without attributing to whom the quote belongs.
That, and all we actually have of Paul is a few letters that he wrote (and not even all of the letters he wrote). It is probable that he spoke much more about Jesus while he was preaching. However, we don't actually have any of his sermons. But it is quite probable that he spoke much more about Jesus in those sermons, and we can be confident about this as Jesus was essential to the movement.
I don't necessarily agree with that, but it does make sense.
Actually he does. He mentions that Jesus was born of a woman. He was born according to the flesh. He was born a Jew, and was the descendant of David. He was crucified, died, and was buried. It's not much, but Paul also wasn't writing a biography. That and we only have a very small portion of what Paul taught.
It true Paul wasn't writing a biography. But the things he does mention about Jesus are very vague. But the point of the thread was about the historicity of Jesus, so using Paul would not be a very wise thing to do.
Paul is confusing. There are some that believe he contradicts himself. There are those who believe that just shows that his beliefs were evolving. And then there are those who acknowledge the contradictions, and then see if they can be figured out. Most of the time, they can be figured out.
If the consensus among Christians was that Paul's thoughts were evolving, and that his, nor Christianity's beliefs as a whole, were not monolithic, I could have an easier time accepting him. I'm aware of the fact that Christians, throughout the centuries, have done their best to figure out the contradictions of Paul. Some can be rectified. I don't necessarily agree with all of them, however.
Most of what he writes really isn't in stark contrast to what Jesus taught. The big difference is that Paul taught to Gentiles. Other than that though, they were generally the same. More so, Paul was supported by the Jerusalem Church, which directly continued the work of Jesus, and was composed of the brother of Jesus, and some of the head disciples of Jesus. And Paul submitted to them. When they had disagreements, Paul may have argued his case, but he ultimately submitted to what the Jerusalem conference said.
I'm not so sure that the idea that Paul and Jesus were in general agreement are so cut and dry as some people think. I'm also of the same opinion that he and the Jerusalem church were not so cordial with each other. With the first one, I can offer some of my ideas, with the second, it's more of a personal feeling I get.
In addition, Paul even collected money for the Jerusalem church, which again shows us that he was connected to them. If Paul was teaching such stark contrasts, there is no reason for us to think that the Jerusalem church would allow Paul to continue. They could strip him of any authority, and that would be a major blow to Paul.
While this does indeed seem to be the case, we can take instances from today. Various different Christian denominations will often help out those from other denominations, especially during times of catastrophe, such as was the case here. Not only that, but some Christian denominations will even go so far as helping out other religions.
In the end though, I think Paul alone shows us that Jesus existed. We could argue whether or not he was a good man or not, if he was corrupt, or what not. However, Paul was a contemporary of Jesus. He may not have met Jesus, but he met James, the brother of Jesus, as well as Peter and John, who were head disciples of Jesus. More so though, we are told that Paul met with Peter, and spent time with him.
This would seem to make a good case, but I do have a problem with it. Even though Paul might have met with Peter, James, and the others, his knowledge is still second hand. To say that Paul's friendship with Peter and James is acknowledgement of the existence of Jesus, is to assume that Peter and James were not being deceptive. What I'm trying to do is see if there's anyway the Bible can be used as a tool to gather historical information, so skepticism is required. To take Peter and James at face value, is to apply the religious notion that they would have no reason to be deceptive, and were telling the truth. Now, they might have been, but they may not have.
So Paul may not be a first hand account on Jesus, but he bases his information off of first hand accounts. And really, that should be enough. Much of our information concerning any historical figure is not from the author knowing the character, but them basing their information off of first hand accounts. In that regards, I see no reason to make an exception for Paul, and just dismiss him.
I can agree with your idea that information about historical figures can come from second hand accounts. However, when that is the case, the character, not only of just one person, but many more come into play. Like I stated above, I don't necessarily take Peter and James at face value. And it's not necessarily that I think that they're being purposefully deceptive, but could simply be mistaken. I've thought of an example, it's not a great one, but it should illustrate my position: let's take the Loch Ness Monster. Many people believe that it exists. There are stories going back hundreds, if not over a thousand, years of people reporting sightings of this creature. However, we have absolutely no physical evidence of it's existence. Every video and photograph taken has proved either to be a hoax, a case of mistaken identity, or something else that can easily explain away the creature. But, we have accounts of people who have friends or relatives who have seen it, sometimes we even have first hand accounts. Should these accounts be taken at face value? Most of the people who have sighted this creature seem to be honest, and would have no reason to lie about it. And yet I, as well as many other people, have a hard time believing that this creature exists. Now, take UFO's. There's plenty of evidence of their existence, and it's a phenomenon that I accept happens. The reason being is that there is corroborating evidence to back up the claims of the stories of some people who have witnessed UFO's. So I try to look at this topic in a similar light.