Ummm...
Jesus journal maybe... or...
One of Paul's long winded letters...or...
A few pages of Torah swiped from the local Jewish synagog...or...
Few pages of philosophy from one of the locals... or...
Your guess goes here!
It's obvious from the early church fathers writings that many Christians were learned and fairly well read for their time. I am sure that they introduced written works pretty early on and even documented their own experiences for posterity... which has now become our Bible. Wonderful isn't it?