Colin J. Hemer’s book The Book of Acts in the Setting of Hellenistic History prompted me to think about why Luke wrote Acts. The beloved physician tells us he wrote his Gospel for the “most excellent Theophilus” (Luke 1:1-4), who is likewise mentioned in its sequel Acts (1:1), but the point of the writing and then dissemination of the latter is really not made explicit.
Think about it: Among all the books of the New Testament, the question of what motivated the author is special here. The New Testament epistles each contain within them, explicitly or implicitly, some indication of why the author wrote them: to address the problems in a problematic congregation, to give pointers to a younger evangelist, to explain at greater or lesser length some theological points to other Christians, and so forth. The need to tell people about the birth, life, teachings, death, and Resurrection of Jesus Christ — the biographies we have as the Gospels — is explained, for starters and as if an explanation is really needed, by the Great Commission. After the Revelation of the end times to John by Jesus Christ, the former’s decision to share this revelation with others is likewise self-evident: How could you not tell your fellow Christians about it?
But, as I say, Acts is a little different. It is history of a nonbiographical sort, covering many years and many places — and indeed each part of it might have been thought necessary for a separate reason. The very first part gives us more of Jesus and his teachings, which is obviously of importance to Luke’s brothers and sisters in Christ; the last half tells us about Paul, an important and inspiring apostle whose story is not told elsewhere and which Luke witnessed firsthand; the part in between about Peter and the other apostles in the early days of the church includes one crucial (literally) episode after another (the Holy Spirit coming to all Christians per the Pentecost, inspiring miracles and martyrs, Christ’s doors opening wide to the Gentiles beginning with Cornelius, and so forth). I suppose the short answer to the question I’ve posed in the title above is, “To inspire and encourage.”
Note by the way that I am not ignoring the role of the Holy Spirit in spurring Luke to decide to write, and certainly not in the words he actually wrote once he made that decision. One could just as easily have styled this post, Why did the Holy Spirit want Luke to write Acts?