In my former book, Theophilus, I wrote about all that Jesus began to do and to teach 2until the day he was taken up to heaven, after giving instructions through the Holy Spirit to the apostles he had chosen. 3After his suffering, he showed himself to these men and gave many convincing proofs that he was alive. He appeared to them over a period of forty days and spoke about the kingdom of God. 4On one occasion, while he was eating with them, he gave them this command: "Do not leave Jerusalem, but wait for the gift my Father promised, which you have heard me speak about. 5For John baptized with water, but in a few days you will be baptized with the Holy Spirit."
6So when they met together, they asked him, "Lord, are you at this time going to restore the kingdom to Israel?"
7He said to them: "It is not for you to know the times or dates the Father has set by his own authority. 8But 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."
Acts 1 introduces many themes that are important to the whole book: Jesus' life and ministry, his sufferings as a fact predicted in the Old Testament, the importance of and evidence for the resurrection, the importance and power of the Holy Spirit, the priority of witness, the Great Commission with its scope extending to the ends of the earth, the missionary attitude as opposed to parochialism, the kingdom of God, the importance of truth and of Scripture in the Christian life, the role of the apostles, the ascension and second coming of Christ, and the importance of prayer and fellowship. As such it is a key to understanding the book of Acts. Because of this we will devote comparatively more space to it even though it is one of the shorter chapters.
The opening section of Acts contains a prologue along with a historical introduction. The author begins by referring to his "former book," gives the name of the recipient (Theophilus), and summarizes the contents of the earlier book (the Gospel of Luke). Theophilus means "friend of God" or "loved by God," but it is unlikely, as some (e.g., Origen) have suggested, that this name is a symbol for an anonymous person or group of people. This particular name was in use at that time, and the description of Theophilus as "most excellent" (see Luke 1:3) suggests that a real person is meant. "Most excellent" could suggest that a high government official is being addressed, but that is not a necessary inference as it was also used as a "form of polite address." In those days, it was common for books to be dedicated to distinguished persons.
If Luke's first volume describes "all that Jesus began to do and to teach until the day he was taken up to heaven," we can assume that this second volume describes what he continued to do and to teach (through his Spirit) after he was taken up. Luke uses the word "all" in both the Gospel and Acts in a general way that the context must define. Thus, "we cannot assume he meant his Gospel to be any more exhaustive than Acts."