The authors of both
Matthew and
Luke relied on
Mark and 'Q' as their main source documents, but both authors then elaborated the Marcan material and added material of their own or from otherwise unknown sources.
Material that is unique to
Luke includes the birth of John the Baptist and his supposed relationship to Jesus; the entire nativity story of Jesus (the nativity story in
Matthew is entirely different and incompatible); the genealogy of Jesus back through Joseph (again,
Matthew has a genealogy of Jesus back through Joseph, but it is entirely different and incompatible); the story of Jesus in the temple at the age of twelve; the Prodigal Son and the Good Samaritan are parables unique to
Luke; the story of Mary, Martha and Lazarus (the story in John is entirely different to the parable in
Luke); Jesus telling the disciples to cast their nets on the other side, and they caught many fish (this story is in
John, but not until after the resurrection of Jesus); the ascension of Jesus to heaven is not in
Matthew nor the earliest manuscripts of
Mark, but a somewhat similar story is in the "Long ending"
* to
Mark.Footnote*The Long Ending does not exist in the earliest manuscripts of Mark's Gospel, but was added much later, to more or less harmonise
Mark with
Matthew and
Luke. There was also, at one stage, a "Short Ending".