1. Who wrote Acts?
Luke, the beloved physician, is the author of both the Gospel bearing his name and the book of Acts. He was not an original disciple (Luke 1:2) but was a traveling companion of Paul. While Luke was not an eyewitness of the events recorded, he was an eyewitness of a significant portion of events narrated in the second half of the book of Acts. Luke's close association with the apostle Paul ensured that the canonical criterion of apostolicity was met. Paul endorsed the Gospel of Luke in 1 Timothy 5:18, so it can apply to the book of Acts as well.
2. When was Acts most likely written?
There are a few who date Acts after AD 75, and it is based on how one addresses the Synoptic Problem (typically in terms of Markan priority) and dating Mark in the mid to late 60s.
An early date before AD 70 is preferred. The abrupt ending of Acts 28, the neutral to friendly presentation of the Roman Empire, no mention of the Pauline Letters, and no mention of the Jewish war and its events support an early date.
3. Who was Theophilus?
Little is known about Theophilus since there is no mention of the man in the rest of the book of Acts. Most likely, he was LUke's literary patron, in which case he would not only have paid the price of publication but may have housed LUke during the book's production and made the manuscript available for copying subsequent to its completion.
4. Where was the book of Acts most likely completed?
Luke most likely wrote the book of Acts in the city of Rome. If Luke had caught up in time with Paul so that the apostle was awaiting trial in Rome at the time of the writing, then Luke was with Paul when he wrote the book. This was the view of Irenaeus (ca. AD 130–200), Eusebius (ca. AD 260-340), and Jerome (ca. AD 345 –420). 
5. What are the major proposals regarding the purpose of Acts?
Proposals regarding the purpose of Acts include evangelism, an apology or defense of the Christian faith, Paul's legal defense, various theological concerns, the historical basis of the establishment and growth of the kingdom of God, and edification. One must take into account that Acts is a sequel to Luke's Gospel.
The literary structure of the book points to the expansion of the church from Jerusalem to the rest of the world, empowered by the Holy Spirit. So one primary purpose is for the book to be used as a historical apologetic that explains God's plan for extending the gospel to the Gentiles while including believing Jews as well.
6. Why is the question regarding genre important for studying Acts?
The answer to the question regarding the genre of Acts will help one to identify the expectations one should have when approaching the book. There is a big difference if the Book of Acts is a collection of legends or a serious historical narrative.
The early church fathers like Clement (Stromatreis 5.12) and Jerome (Epistle 53.8), familiar with the different literary genres, referred to the book as a "history." The preface of Luke and Acts also supports the author's intention to write an accurate historical account.
7. Why is the book of Acts considered historically reliable?
The Book of Acts has been verified as reliable in its accurate references to geography, sociology, and specific events.
- topography of Jerusalem (Acts 1:12, 19; 3:2, 11)
- geography of Asia Minor
- specific people (title of emperor was Augustus in Luke 2:1 but Sebastos on the lips of a Roman official in Acts 25:21, 25)
- people at Lystra spoke their own dialect (14:11)
- accurate, detailed ancient navigation (chap. 26)
No real reason to doubt the accuracy of Luke's speeches exists if these are understood as reliable summaries of real speeches. A hypothetical conflation theory is not necessary to explain the historical reliability of the Jerusalem Council in Acts 15. The most problematic area for some regarding the historical veracity of Acts is the miraculous elements in the book. But the heart of the issue is not historical; it is a matter of philosophical and theological presuppositions.
8. What are the sources that lay behind the composition of Acts?
Based on the "we" passages, Luke was an eyewitness to much of what was covered in Acts 16–28. This section could come from Luke's personal diary or from his recollection of these events. Paul likely would have been a primary source given his acquaintance with Luke.
For the material in Acts 1–15, "LUke obtained parts of his material by interviewing participants, and that he sometimes edited older traditions by re-interviewing such surviving participants as may have been accessible to him, and that this process accounts for some of the significant 'L-nuances' in the Third Gospel."
Luke's connection to Peter, some written sources (Acts 15:23–29; 23:25–37), eyewitness testimony and personal investigation were means for Luke to obtain the information necessity to write the Book of Acts.
9. What is the basic "blueprint" for Acts, and why?
The basic blueprint for Acts is given in Acts 1:8.
But you will receive power when the Holy Spirit has come upon you; and you shall be My witnesses both in Jerusalem, and in all Judea and Samaria, and even to THE END OF THE EARTH.
- God's plan for the church in Jerusalem and Judea (1:1–6:7)
- God's plan for the church in Samaria (6:8–9:31)
- God's plan for the church to the ends of the earth (9:32–28:31)
10. What is the logic underlying Peter's Pentecost sermon?
Peter's sermon at Pentecost is found in Acts 2:14–40.
- The Spirit had now been poured out.
- Jesus predicted that this would occur once he had been exalted with God and subsequent to his ascension.
- Hence, the coming of the Spirit proved that Jesus had now been exalted.
- Peter quoted the prophecy of Joel 2:28–32 to explain that this was the promised coming of the Holy Spirit.
11. What major issue was discussed at the Jerusalem Council?
The issue discussed at the Jerusalem Council was whether Geniltes had to become Jewish proselytes before they could become Christians. The matter was settled by the testimonies of Peter, Paul, Barnabas, and James adjudicating the matter by citing Amos 9:11. At the conclusion, a letter was sent (15:23–29) that encouraged the Gentiles to abstain from things particularly repulsive to Jews (15:20, 29).
12. What role does the Holy Spirit play in the book of Acts?
God's moving the gospel was accomplished through the activity and work of the Holy Spirit. The arrival of the Holy Spirit at Pentecost signed the beginning of the church and its advancement. The Holy Spirit gave instructions to Philip (8:29, 39), Peter (10:19–20), and Paul (16:6–10; 20:22–23; 21:4). The Holy Spirit empowered the mission and direction of the church and its spread from Jerusalem to the ends of the earth.
Andreas J. Köstenberger, L. Scott Kellum, and Charles L. Quarles, The Cradle, the Cross, and the Crown: An Introduction to the New Testament, 2nd ed (Nashville, TN: B & H Publishing Group, 2016), 393. ↩︎
Köstenberger, Kellum, and Quarles, 395–396. ↩︎
Köstenberger, Kellum, and Quarles, 395. ↩︎
Köstenberger, Kellum, and Quarles, 396–399. ↩︎
Köstenberger, Kellum, and Quarles, 409–410. ↩︎