“The four Gospels... are all anonymous, written in the third person
about Jesus and his companions. None of them contains a first-person narrative ("One day, when Jesus and I went into Capernaum..."), or claims to be written by an eyewitness or companion of an eyewitness. Why then do we call them
Matthew,
Mark,
Luke and
John? Because sometime in the second century, when proto-orthodox Christians recognized the need for
apostolic authorities, they attributed these books to apostles (
Matthew and
John) and close companions of apostles (
Mark, the secretary of Peter; and
Luke, the travelling companion of Paul). Most scholars today have abandoned these identifications, and recognize that the books were written by otherwise unknown but relatively well-educated Greek-speaking (and writing) Christians during the second half of the first century.”
"Lost Christianities" by Bart Ehrman (
2003)
7