It depends upon the journeys. the short answer is that over all the journeys Paul was accompanied by Peter, Barnabas, Timothy, Silas, John Mark (author of the Gospel of Mark) and Luke amongst others.
Because Luke accompanied John on their journey to Rome
Several different fellow-workers accompanied Paul at various times, including Barnabas, John Mark, Silas, Timothy, Titus, Luke, and an unspecified number of others.
Luke was a close associate of Paul and one of his travelling companions on his missionary journeys. In Colossions 4:14 Paul tells the Colossion church that Luke the beloved physician greets them. In 2 Tim.4:11 it states Paul saying "..only Luke is with me" as other associates had left and gone elsewhere. Throughout the book of Acts, the word "we" is used, referring to Luke and other associates travelling with Paul.
Luke traveled with the apostle Paul during his missionary journeys, and he is believed to have written the Gospel of Luke and the Acts of the Apostles in the Bible. Luke was not one of the original twelve apostles chosen by Jesus.
There is no evidence that Luke ever wrote for Paul.
Luke traveled to rome so he would see the over side of the worldi believe he was with Paul... Apparently they were good friends and Luke wrote his Gospel while Paul was imprisoned in Rome around 61AD...
The evangelist Luke, was not among the Apostles during the Passover meal - aka the Last Supper. He would later travel with Paul and write his Gospel and the Book of Acts.
Luke was a companion of Paul, and not a apostle.
Paul accompanied Luke much of the time during his travels, including the perilous voyage to Rome , which is apparent from his use of the first-person plural pronouns "we," "our," and "us" in Acts 16:10-17; 20:5-15; 21:1-18; 27:1-37; 28:1-16. Paul, in his letters written from Rome, mentions that Luke was also there. (Col 4:14; Philemon 24)
Luke was a missionary companion of Paul, for one thing.
Luke was a physician, a doctor of medicine.
Jesus life and ministry is chronicled in the Gospel accounts of Matthew, Mark, Luke and John. Most people think that all four were Apostles, but Luke was not. Luke was a physician and accompanied the Apostle Paul on some of his missionary journeys. Luke also wrote the Book of the Acts of Apostles which chronicled their journey. See the related links for information on Jesus Christ, his life and ministry.