Tradition has it that the author of the gospel of “LUKE” and “ACTS” of the Apostles were written by the same individual, and that is by, Luke the ‘beloved’ Physician. Although it is difficult to prove with absolute certainty, there may have in fact been more than just a single source for the events recorded in the book of ACTS. Almost the entire first half of the book highlights the ministry of the Apostle Peter, and there is no internal or external evidence that Peter and Luke ever knew each other.
Not only that, but the author of ACTS would most likely be acquainted with both Peter and Paul. Some have argued that the Greek text used in the gospel of LUKE and ACTS is more of the classical style and more advanced than ‘KOINE’(common Greek) used in other New Testament writings; but considering Paul’s ministry and making converts from Hellenistic Jews among the epicenter of Greek culture in Europe and the civilized world at that time, then it should not come as too much of a surprise.
Luke is first mentioned in the book of COLOSSIANS, which is well after the events covered in ACTS and at this time the Apostle Paul is already a prisoner in Rome (??). There is a possible clue to figuring out who Paul’s biographer is during the Second Missionary journey as recorded in Acts 15: 36 thru 16: 10. Up until that time, everything in ACTS had been recorded in the ‘third person,’ but after arriving in Troas and on to Macedonia, the verb tense shifts to the ‘first person’ (“we, us, our”). This pattern continues in the following passages in ACTS 16: 10; 20: 5-7, 13-15; 21: 1, 3-8, 10-18; 27: 1-7, 18-20, 27, 29, 37; 28: 1-2, 10, 12-16.
All of Paul’s other friends and helpers who accompanied him at this time are accounted for, such as Gaius and Aristarchus (Acts 19: 29), who is included with Sopater of Berea, the son of Pyrrhus, Secundus of the Thessalonians, Timothy; Tychicus and Trophimus (Cp. 21: 29) of ASIA (Cp. Acts 20:4). In the next verse (20: 5) the author writes: But these had gone on ahead and were waiting for us at Troas. One could point out that Silas might be the author, but he is included in previous narratives.
Again, the city of Troas comes up and the only other person mentioned in the New Testament with regard to the city of Troas is none other than Titus (II Corinthians 2: 12-13); although he isn’t mentioned specifically by name in ACTS (“we?”;16: 10). Perhaps this circumstantial evidence is not enough to dissuade the strong opinion that holds firmly to the traditional viewpoint and although it may not conclusively certify Titus as one of the authors of ACTS, it certainly casts some doubt on whether or not Luke the Physician is the author of the book.