The Gospel of Luke is a composite work. It is based on Luke’s own work, called Luke’s History here,Â plus passages taken over with minimal changes to grammar and syntax from the Gospel of Mark.
Luke’sÂ own contribution to the work that bears his name is quite easy to establish. It is the Gospel of Luke, minus the Markan material. It includes Luke’s primary source, bits from the main source behind the Gospel of MatthewÂ and other material as well. We shall call Luke’s creative work Luke’s History, to distinguish this somewhat shorter work from the well known Gospel of Luke.
Creating Luke’s History
If we accept Lukeâ€™s testimony, Luke’s HistoryÂ can be attributed to Luke’s own research, wherein he said at the beginning of his work that he had examined the matter thoroughly, drawing on existing reports and eyewitness testimony. There are many indications of this kind of research in Lukeâ€™s History, not the least of which are the unique anecdotes, parables and other teaching episodes found in that work.
It is tempting to look for Luke’s primary source in the text of the Gospel of Matthew, but this temptation should be resisted. It isÂ more likely that he used a primary source that was a quite distinct accounting of Jesusâ€™ life. Even the change in title from the â€œSermon on the Mount,â€ found in Gospel of Matthew,Â to the â€œSermon on the Plain,â€ found in Lukeâ€™s History, can be seen to have been deliberate, and intended to signify that this was a different reporting of the same events.
Luke’s primary source
Lukeâ€™s primary source was able to do for him something that Matthew did not strive to achieve: he put all his material into the context in which he had heard Jesus say these things. This means that Luke’s account is in a quite different sequence to that found in the Gospel of Matthew, as well as many of the stories being different.
Excluding the Jesus’ final week, Luke’s primary source is likely to have included:
(Luke was not the only one to use the material that I call his primary source, Mark also used it, but only to order his material. Mark gave all this material his own interpretation, basing his gospel account on Peter’s preaching, not on Luke’s primary source.)
Luke’s supplementary material
Luke himself indicated that he had access to written sources. This certainly would have included the text that lies behind the Gospel of Matthew. He was able to supplement this information during the two years that he accompanied Paul while the latter was imprisoned in Caesarea (in Israel). This happened ca. 58 to ca. 60. In any event, it is certain that eyeÂwitnesses to Jesusâ€™ life and teaching would have been still alive at this time, so there was no barrier to Luke being able to carry out this kind of work at that time, even though some eyewitnesses would have already died.
Whatever his sources, with have little reason to doubt the additional information he provided, such as Mary’s story and the accounts of Jesus’ rejection at Nazareth, the women who accompanied Jesus, the Good Samaritan, and so on. He ended his account with the Walk to Emmaus and an account of Jesus’ ascent to heaven from a hill in Jerusalem.
Completing the work
It is probable that Luke completed his two volume work (Lukeâ€™s History and Acts) around AD 62, before Paul died in Rome. At least, this is the simplest explanation of the abrupt ending of Acts.
Gospel of Luke
Since we have no reason to believe that Mark came to Rome until after ca. 62, this leads us to think that the Gospel of Mark was written after Lukeâ€™s History was completed.
Some years later, according to this scenario, when the Gospel of Mark was available to him, Lukeâ€™s Editor interleaved Markâ€™s account into Lukeâ€™s History, making the Gospel of Luke as we have it today. This can be considered to be a second edition of his work (and the only one that has survived). If anyone revised the ending of Acts, that version has (unfortunately) not survived.
Therefore, the Gospel of Luke consists of Lukeâ€™s original text plus elements we can easily identify as coming from the Gospel of Mark. Lukeâ€™s work first appears in the writings of Clement of Rome, ca. 96. We can guess that the Gospel of Luke, as we have it today, was completed around the same time. We do not know where it was written, but if pushed to make a suggestion I would propose Rome on the grounds that Clement seems to have used Luke’s work more than Matthew’s.