This author reportedly traveled with Paul and wrote down everything he experienced.
While today we often refer to the fours Gospels as, Matthew, Mark, Luke and John, St. Jerome nicknamed one of these books, “Paul’s Gospel.”
He was referring to the Gospel of Luke, based on a tradition that Luke was a companion of Paul for some of his journeys. Luke then based much of what he wrote down from his conversations with Paul.
Luke, along with Mark, was a Gospel writer who did not have first-hand experience of Jesus’ life. He may have been one of the 72 disciples commissioned by Jesus, but it is generally believed that Luke was not present for most of Jesus’ ministry.
This means that Luke had to rely on alternative sources for his material. One traditional claim is that Luke was able to interview the Virgin Mary, and that is why he has a great amount of material on Mary and the early life of Jesus.
Whatever the case may have been, the Gospel of Luke and the Acts of the Apostles are normally seen as a single volume written by the same author. In the book of Acts, there is a distinct change in the narrative when the author begins using the pronoun “we,” indicating a first-hand experience.
And a vision appeared to Paul in the night: a man of Macedonia was standing beseeching him and saying, “Come over to Macedonia and help us.” And when he had seen the vision, immediately we sought to go on into Macedonia, concluding that God had called us to preach the gospel to them. (Acts 16:10)
The author only uses this pronoun when referring to travels with Paul, indicating that he was a traveling companion with the apostle.
Paul also mentions Luke in his letters. For example, in his second letter to Timothy Paul writes, “Do your best to come to me soon. For Demas, in love with this present world, has deserted me and gone to Thessalonica; Crescens has gone to Galatia, Titus to Dalmatia. Luke alone is with me” (2 Timothy 4:9-11).
While modern biblical scholars continue to debate the authenticity of such a proposition, many believe that the tradition of St. Luke traveling with St. Paul is a valid one. His Gospel then could rightly be nicknamed “Paul’s Gospel.”