Paul never met Jesus. You are correct but he did have his disciples. 4 "books" gospels were written by them. Those are the witnesses. They are 4 different men writing about the same things. Look it up. Each book has a separate historic date that they are written. Yes they are written almost at the same time but not together. How can you not believe in this history but you can believe in other history books. They are written the same. By men who bear witness to the events at hand.