The book of Acts begins with the phrase, “In my former book,
Theophilus.” Acts is the second volume of Luke’s history of
the Christian church. The gospel bearing his name is the
“former book” mentioned in Acts 1:1. Luke was a physician, a
traveling companion of Paul, a historian and a theologian. His
two volumes combined make him the most prolific author in
the New Testament. The gospel of Luke and the book of Acts
were probably written during the two years that Paul was
imprisoned in Rome.
Luke’s purpose in writing could simply be to record the history
of the Christian church, but many theologians believe he
wrote in order to provide Paul and other Christians with a
legal defense for their faith. Luke writes consistently to prove
three things: Christians are not a political threat to Rome;
the Christian church is the continued ministry of God in the
world; the Christian church is a diverse, but united group of people who have received salvation in Christ.