Almost all that we know about Luke comes from the New Testament. He was a physician (Col 4:14) and a companion of Paul on some of his missionary journeys (Acts 16:10ff; 20:5ff; 27-28).
Material found in his Gospel and not elsewhere includes much of the account of Our Lord's birth and infancy and boyhood, some of the most moving parables, such as that of the Good Samaritan and that of the Prodigal Son, and three of the sayings of Christ on the Cross: "Father, forgive them," "Thou shalt be with me in Paradise," and "Father, into thy hands I commend my spirit."
In Luke's account of the Gospel, we find an emphasis on the human love of Christ, on His compassion for sinners and for suffering and unhappy persons, for outcasts such as the Samaritans, tax collectors, lepers, shepherds (not a respected profession), and for the poor. The role of women in Christ's ministry is more emphasized in Luke than in the other Gospel writings.
In the book of Acts, we find the early Christian community poised from the start to carry out its commission, confident and aware of Divine guidance. We see how the early Christians at first preached only to Jews, then to Samaritans (a borderline case), then to outright Gentiles like Cornelius, and finally explicitly recognized that Gentiles and Jews are called on equal terms to the service and fellowship of Christ.
Luke makes many casual references throughout his writings (especially in Acts) to local customs and practices, often with demonstrable and noteworthy precision. To mention just one example, he refers to two centurions by name, Cornelius in Acts 10 and Julius in Acts 27, and he calls them both by nomen only, rather than by nomen and cognomen (Sergius Paulus in Acts 13;7) or cognomen only (Gallio in Acts 18:12), as he does when speaking of civilian officials. It is a distinction that would have been routine at the time that Luke is writing about, but one that had largely died out by, say, 70 AD. His preserving it shows either that (1) he wrote fairly close to the events he described, or (2) he was describing persons and events on which he had good information, or (3) he was an expert historical novelist, with an ear for the authentic-sounding detail.
Luke is commonly thought to be the only non-Jewish New Testament writer. His writings place the life of Christ and the development of the early Church in the larger context of the Roman Empire and society. On the other hand, his writings are focused on Jerusalem and on the Temple. His Gospel begins and ends in the Temple, and chapters 9 through 19 portray Jesus as journeying from Galilee to Jerusalem. Similarly, the Book of Acts describes the Church in Jerusalem (and worshipping in the Temple) and then describes the missionary journeys of Paul as excursions from and returns to Jerusalem.
What writer wrote more pages of the New Testament than anyone else? If you say Paul, try again. In my pocket Bible, Acts and the Gospel of Luke occupy a total of 60 pages, while all the letters traditionally attributed to Paul (not counting Hebrews) total 56.
The writer of the Third Gospel and the Book of Acts does not give his name in his writings. (Except for Nehemiah, no Biblical writer of a narrative book does.) He does claim to be a traveling companion of Paul, and his interests and vocabulary suggest that he is a physician. Since Paul tells us that he had a companion named Luke who was a physician, the conclusion that Luke is the writer we are looking for is reasonable.
Was the two-volume work Luke-Acts in fact written by a companion of Paul?
Scholars are not agreed on the answer.
By and large, most German writers favor a negative answer. Their reasons are that (1) the chronology of Paul's life found in the Book of Acts presents certain apparent conflicts with that found in Paul's letter to the Galatians, and that (2) the writer seems unfamiliar with the geography of Israel.
On the other hand, most English scholars favor an affirmative answer.
Their reasons are that the "We" sections in Acts (the sections in which the author explicitly claims to have been present at the events he describes) contain a wealth of circumstantial detail that make invention extremely unlikely.
Thus, for example, Mr. James Smith of Jordan Hill, FRS, having sailed a vessel over the same route described in Acts 27-28, argues in his book, The Voyage and Shipwreck of Saint Paul, or at that the account must have been written by someone who had sailed that route.
It used to be a popular theory that the writer had somehow gotten his hands on a travel diary of the real "Luke" and incorporated it into his work.
However, a detailed analysis of the writing style of various sections of the work shows none of the differences that would be expected on this theory.
Scholars on the affirmative side generally answer the negative objections mentioned above by supposing that (1) the conferences mentioned in Acts 15 and Galatians 2 are not the same conference, and that (2) Luke uses the word "Judea" sometimes to mean the southern portion of the land of Israel, and sometimes to mean the whole land.
For some comments on the historical reliability of the opening chapters of the Gospel of Luke, read the following:
The Infancy Narratives in Matthew and Luke, part 1
The Infancy Narratives in Matthew and Luke, part 2
Questions About the Genealogies
The Virgin Birth
written by James Kiefer