Tradition holds that Luke was a physician, and whether this title would have meant quite the same thing in his day as it does today is probably a matter of conjecture, but one thing is certain; whoever Luke was or whatever his profession may have been, he was certainly a well educated man, as evidenced by the quality of his Greek. It is also clear that he was an associate of Paul, as we will see later on in the story, an eyewitness too many of the things he describes here.
The theme and overall context of Acts rings clearly through the ages:
But you will receive power when the Holy Spirit comes on you; and you will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth. (1:8) Acts has multiple phases and deals with many trials, tribulations… and triumphs, but this will remain the major theme, that they will receive power with the Holy Spirit, power to be the very witnesses of Jesus Christ throughout the world. Thus, we might accurately consider Acts to be the book of Genesis of the Church itself, for what was begun way back in Luke’s day, is an ongoing story from that time until this very day, a story in which both you and I have a part to play.