In light of that conversation, I ran into a good expression of this issue and pass it along for the members of our study, but also for anyone else who wants to engage a serious study of this New Testament writing.
Historical questions are not irrelevant to the study of Acts. It may not make a difference whether or not a man named Macbeth really lived, but it does make a difference whether or not a man named Jesus lived. A man named Jesus lived. His followers staked their lives on his life. What is the meaning of this?
The prologues say that a major purpose of Luke-Acts is to provide an orderly and accurate account of what has happened (Luke1:1-4; Acts 1:1,2). A rigid dichotomy between historicity on the one hand and free Lukan composition on the other hand is unjustified. There is much in Acts that does not conflict with the information in Paul's (earlier) epistles. Luke is writing neither theological romance nor secretly received personal revelation. He is interpreting the stuff of history, actual events. History and proclamation are not exclusive categories. To preach Christ is to preach history "that you may know the truth" (Luke 1:4)
Modern people often define history as an objective reporting of the facts. But scholarly objectivity is a myth which has been put to rest by the studies of people like Paul Ricoeur who stress that all history is written because of certain subjective interests of the historian ... Whoever looks for nothing in history finds nothing. Luke is a true historian, even if an ancient one, who is looking for abiding meaning within "all that Jesus began to do and teach" (Acts 1:1).
William H. Willimon, Acts, pages 6-7.