Best evidence for a historical Joshua ben Joseph

[Lumpenproletariat]

Paul was not an eyewitness to the resurrection.

And Cicero was not an eyewitness to the Caesar assassination. But he says something about it, making him an important contemporary source, just as Paul is an important source for the Resurrection, having been contemporary to it and knowing of it. Having the later sources which tell most of the story, but also a contemporary source mentioning it helps greatly to establish that the event did happen.

He never knew Jesus the man.

99% of our ancient history sources are writers who did not know the people they wrote about. You can make a good argument that Paul and several other contemporaries didn't encounter Jesus directly, but very soon after the event he obviously became attracted to it and got involved, so that something unusual must have happened and was causing confusion and trouble and conflict. This is easily explained if the Resurrection event actually did happen.

Before this event there was not yet enough to attract Paul and others, but afterwards it changed, because something unusual must have happened. Paul quickly learned of it, got involved, and then had a "conversion" experience after first having been hostile to the new "cult" -- all this is explained if the Resurrection really happened, because he became convinced of it after finding out more of what really happened.

So it all makes sense that he did not know Jesus directly, but became a believer after hearing the facts of what had happened. His mind changed after he had checked into it and learned what had happened. This indicates that he changed not philosophically, but from something new he learned, about events which had happened.

Apparently Paul was not even aware of some of the events told about Jesus in the later Gospel accounts, . . .

That he didn't mention an event doesn't mean he wasn't aware of it. He omits everything prior to the night of the arrest, at the very end, mentioning nothing of what happened earlier. That Paul says nothing of what happened prior doesn't mean there was nothing prior or that the earlier reported events are less credible. Rather it means his interest is only in the death and resurrection.

. . . events told about Jesus in the later Gospel accounts, as if they were later embellishments.

No, that's like saying we can't believe anything about Julius Caesar, or the assassination, except what's reported in Cicero, so all those facts you know about Caesar are later embellishments, because Cicero "apparently" was not even aware of them.

Maybe it's a mystery why Paul wanted to ignore everything about Jesus prior to the very end. Whatever the explanation, it doesn't negate the evidence we have from others who do report what happened earlier. Had Paul given us anything at all of the earlier events, then his omission of something might be significant. But he omits everything earlier, not just the events reported in the Gospel accounts. So this omission gives us no clue whatever about what did or did not happen, or what's only a later embellishment vs. what really happened.