As Paul sends greetings to the church at Rome from the prominent brethren with him at Chenchrea, Corinth’s eastern harbor in Achaia (Romans 16:1), he mentions Timothy, his fellow worker, and three kinsmen: Lucius, Jason and Sosipater (Romans 16:21). Does Paul mean that these men are simply Jews, or is he referring to his extended family, i.e. blood relatives? In other words, is Lucius related to Paul? If so, then Luke, as shown in previous blog-posts, the writer of the third Gospel is not only a Jew, but one of Paul’s extended family. Can this be logically deduced from the Scriptures?
Using a concordance one would find that kinsman (G4773) in Romans 16:21 is used 12 times in the New Testament in 9 different places. It usually refers to one’s extended relatives. In Luke 1:36, 58 it refers to Elizabeth’s extended relatives. In Luke 2:44 it refers to Joseph’s and Mary’s extended relatives. In Luke 14:12 Jesus tells us not to always invite our relatives to dinner but rather those who are unable to return the kind gesture. In Luke 21:16 Jesus points to our relatives who will persecute us, because of our association with him, and in Mark 6:4 Jesus refers to a prophet who is rejected by his relatives. John 18:26 tells us Peter cut of the ear of one of the high priest’s relatives, just before Jesus was taken away. Acts 10:24 shows Cornelius inviting his relatives to wait with him for the arrival of Peter.
The final two places of four occurrences of the word are found in Romans. In Romans 16:7 & 11 Paul seems to be referring to his relatives in Rome, while in Romans 16:21 he speaks of his relatives with him at Corinth. The single Scripture that undoubtedly refers to the nation of the Jews is found in Romans 9:3.
Why should we conclude that Romans 16:7, 11, & 21 all refer to Paul’s relatives either at Corinth or at Rome? First of all, Paul is writing the epistle to Rome cir. 56 AD. At this point in time Christianity was viewed as a Jewish movement. Most believers were Jews. It would be wrong, then for Paul to imply that so few Jews were at Corinth and Rome. The majority of church membership in both locations had to be Jewish. Secondly, why isn’t Timothy mentioned as one of Paul’s kinsmen, if Paul is simply referring to Jews in Romans 16:21? Moreover, why aren’t Priscilla and Aquila, mentioned in Romans 16:3 included as Paul’s kinsmen as he mentions those who are in verses-7 or 11? After all, if Priscilla and Aquila had to leave Rome when Claudius expelled the Jews (Acts 18:1-3), certainly they were Paul’s kinsmen in that sense. Therefore, it is easier to believe the six people mentioned in Romans 16:7, 11 & 21 were members of Paul’s extended family. 
If this position is logically sound, then Lucius, a Jew and a relative of Paul (Romans 16:21) is not only with Paul at Corinth, but is the only Luke traveling with him to Jerusalem (Acts 20:6; 13-15; 21:1-17). This suggests that he is the author of Acts, and, if he is the author of Acts, his introduction to Theophilus at Acts 1:1 refers to another thesis, which was written before that one, showing that the author of Acts is also the author of the Third Gospel. This author is the Luke of Colossians 4:14 and 2Timothy 4:11, the Lucius of Romans 16:21 and Acts 13:1, and he is an eyewitness to at least some extent of Jesus’ words and deeds.
 This study is based upon my reading of John Wenham’s Identification of Luke, Evangelical Quarterly 63:1 (1991), 3 – 44
 See my study: What about Doctor Luke of Colossians?
 See this, my present study, and Lucius of Cyrene
 See my studies: Was Luke an Eyewitness and The Anonymous Disciple.