The Gospel According to Luke
Scholars who study Luke generally refer to "Luke-Acts," a two-volume set. Luke tells the story of Jesus, while Acts tells the story of the early church. Both of these works are believed to have been written by the same author, sometime around 80-90 CE. Togehter, Lk and Acts take up about one-fourth of the NT.
These works were traditionally attributed to Luke, the "beloved physician" (see Col. 4.14; 2 Tim. 4.11) and Paul's coworker (Phlm 24). Is this designation accurate? There is evidence on both sides of the issue, but we can't know with certainty one way or the other. Because of the lack of decisive evidence, most scholars assume anonymous authorship of Luke. (For a balanced discussion of the authorship of Lk, see Robert C. Tannehill's commentary on Luke in the Abingdon New Testament Commentaries series, 20-24.)
Whoever the author was, the Gospel of Luke is not an eyewitness account, since the Luke to whom this gospel is attributed was not a disciple. On the other hand, if the traditional designation of authorship is correct, Acts could be, in part, an eyewitness account.
Lk's author was a skilled writer with a very good command of Greek. He writes in a higher style than the authors of Mt and Mk.
Like Mt and Mk, Lk has his own theological emphases. He demonstrates a concern for the poor, an emphasis on Jesus' prophetic nature, the importance of the Holy Spirit, and a concern for the delayed parousia. Only in Luke do we get the parables of the Good Samaritan, the Prodigal Son, and the lesser known Rich Man and Lazarus.
Lk's gospel was probably written by a church comprised mainly of gentiles, although there is some evidence in the text that there may have been Jews in this church, as well. Three is less hostility toward Jews than we find in Mt, as well as less emphasis upon adherence to the Jewish laws. There is also an emphasis in Lk on the gentile mission.