Is this the next skeptic meme?
I've seen a couple of people claim Paul's Jesus wasn't a historical figure — that He was either pure fiction or perhaps a spiritual figure who died and rose all within another world.
Their evidence: He never talks about Jesus' life. If we had only the writings of Paul, we would know very little about Jesus' life and ministry. The Gospels, being later than Paul's letters (and probably all the other epistles), could then be fiction, stories created to give life to Paul's mystical savior.
Utter crap? Absolutely. Mostly this argument boils down to "I wouldn't have done it this way, so it's wrong." But that doesn't mean we don't have to address it.
It's true that Paul, as well as the other epistle authors, doesn't say much about Jesus' mortal life.
There are plausible explanations for this. Mostly, I'd say the New Testament epistles are an extended commentary on the crucifixion and resurrection of Christ. His ministry and teachings aren't the focus of that part of the New Testament.
But is is possible that Paul was preaching a fictitious, or at least purely "spiritual," Jesus?
You can argue against this from a number of things Paul wrote. Most of it, though, is theological — specifically, things that would make no theological sense unless Jesus was real. But since skeptics don't think any of his teachings make sense, that's not a helpful line of thought.
But Paul said three things that place Jesus firmly in real history:
Jesus was descended from David (Rom 1.3).
Though there are skeptics today, it's ridiculous to think Paul thought David was not a real person. And Jesus, according to Paul, was really descended from that real person.
There are witnesses to His post-resurrection appearances (1Cor 15.6).
Paul claims there are witnesses to an event — witnesses who were still alive, that his readers could find. The event, and therefore Jesus, must have happened in history.
Jesus spoke to Pilate (1Tim 6.13).
If Jesus' death and resurrection were purely fiction or an event of the "spiritual world," He wouldn't have been tried in front of Pilate. Jesus made His "good confession" in front of a real, historical figure, so He must have been one too.
Of course this won't be good enough for anyone who's already made up his mind. But that doesn't mean we have to let them get to us. Whatever reason Paul may have had for not talking about Jesus' mortal life, he clearly knew He had one.