Seriously? LOL.
Matthew, John, Peter, James, and Jude were Apostles and were there for the whole show. Mark wrote his Gospel based on Peter's recollections. Luke based his work on Paul's and probably Mary's recollections. Paul is, as he says, the odd man out, but he checked his understandings against those of the original Apostles.
BS, and it was all written 50-100 years after the death?