Paul was far more interested in the present state of the community than he was in history.
Sure. But he was also a mighty Jesus preacher.
Do you know how preachers often make their sermons? They take something from their lives, some event. Then they build a sermon around that event, showing its relevance to their belief system or the founder of that belief system. Sometimes they look like parables. Mosttimes they are just the stimulus for the sermon.
But Paul never does that -- not in reference to a physical Jesus. I think we all agree on that.
Here's what it would look like with a Paul in the pulpit who actually knew about the historical Jesus:
Last week, as I sailed here to your community, a great storm arose. As it grew, I began to think of the anger which grew in our Lord Jesus as he contemplated the temple money changers. It began slowly -- just a slight breezy disturbance on the calm waves of his mind. But that small thought....
[I'm not gonna write the whole thing. I think you get my point.]
If Paul knew details of Jesus' earthly life -- as he would have if he'd ever been given those details in 35CE Jerusalem -- his letters would have been filled with these kinds of references.
So it seems clear that Paul never heard any details of Jesus life on earth.
Which means that the Jesus followers in Jerusalem never knew the man Jesus.
Which points to a much earlier model for Jesus, and maybe for no model at all.