Luke wrote the book of Acts to show what happened after Jesus rose from the dead: his followers, empowered by the Holy Spirit, carried his message to the world. In Acts 1:1-5, Luke connects his second volume to his Gospel, reminds his reader of the forty days Jesus spent with the apostles after the resurrection, and points ahead to the promised Spirit. The message is clear from the opening lines. Christianity isn’t just a set of ideas to agree with. It’s a message to act on.
Setting the Scene in Acts 1:1-5
Acts is the second half of a two-part work. The same author wrote the Gospel of Luke, and both books are addressed to the same man, Theophilus. Scholars often call the pair “Luke-Acts.” Together they make up more than a quarter of the New Testament, which makes Luke one of its most important writers, even though he never mentions his own name.
Church tradition from the second century onward identifies the author as Luke, the doctor Paul calls his dear friend (Colossians 4:14) and lists among his co-workers (Philemon 1:24). The book itself supports this. Starting in Acts 16:10, the story suddenly shifts from “they” to “we,” as if the author joined Paul on his travels. These so-called “we passages” suggest that much of Acts was written by an eyewitness. If you want to see where Acts fits among the other New Testament books, see What Is the Chronological Order of the New Testament?
Many people today treat Christianity mainly as a worldview. In 2023, the writer Ayaan Hirsi Ali, who grew up Muslim and later became a well-known atheist, published an essay explaining why she had become a Christian. Her reasons focused largely on Christianity as the best foundation for human dignity and freedom. That’s true, and it matters. But Luke would say there’s more. The first followers of Jesus didn’t just admire his ideas. They were changed by them, and they acted.
A Sequel Written to Theophilus
Luke opens by looking back at his first book.
Acts 1:1-2 In my former book, Theophilus, I wrote about all that Jesus began to do and to teach until the day he was taken up to heaven, after giving instructions through the Holy Spirit to the apostles he had chosen.
Notice the word “began.” Luke’s Gospel told the story of everything Jesus began to do and teach. The implication is that Acts tells what Jesus continued to do and teach, now through his Spirit and his people. Jesus wasn’t finished when he ascended to heaven. He was just getting started.
We don’t know much about Theophilus. His name means “friend of God” or “loved by God.” In Luke 1:3, Luke calls him “most excellent,” the same respectful title later used for the Roman governors Felix and Festus (Acts 23:26; 26:25). That suggests he was a person of some social standing, possibly a new believer or a serious seeker who wanted solid answers. Luke explained his purpose at the start of his Gospel.
Luke 1:1-4 Many have undertaken to draw up an account of the things that have been fulfilled among us, just as they were handed down to us by those who from the first were eyewitnesses and servants of the word. With this in mind, since I myself have carefully investigated everything from the beginning, I too decided to write an orderly account for you, most excellent Theophilus, so that you may know the certainty of the things you have been taught.
Luke was a careful historian. He interviewed eyewitnesses and investigated everything so his reader could be certain. The Gospel of Luke is mostly about seeking Jesus, learning the truth about his life, death, and resurrection. Acts is mostly about sharing Jesus. The story moves from learning the message to living it out.
Forty Days of Proof
Luke then summarizes the time between Easter and the ascension.
Acts 1:3 After his suffering, he presented himself to them 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.
The NIV says Jesus gave “many convincing proofs.” The Greek word, tekmērion, was used by ancient writers for decisive evidence, the kind that settles a question. The resurrection wasn’t a vague spiritual feeling among grieving followers. Jesus appeared repeatedly, talked with them, and ate with them. Paul later listed many of these appearances, including one to more than five hundred people at once, most of whom were still alive when he wrote (1 Corinthians 15:3-8).
The number forty shows up at key moments in Scripture: Moses on Mount Sinai, Israel in the wilderness, and Jesus fasting in the desert before his ministry began. Now forty days of personal instruction prepared the apostles for their mission. And the subject was the kingdom of God, the same theme Jesus preached throughout the Gospels.
The end of Luke’s Gospel shows what Jesus was doing during those days.
Luke 24:45-47 Then he opened their minds so they could understand the Scriptures. He told them, “This is what is written: The Messiah will suffer and rise from the dead on the third day, and repentance for the forgiveness of sins will be preached in his name to all nations, beginning at Jerusalem.”
It’s one thing to hear a message. It’s another thing to understand it. Jesus opened their minds so they could see how the whole Old Testament pointed to him. Then he gave them a job: this message must be preached to all nations, beginning at Jerusalem. That sentence is practically a table of contents for Acts. It’s no surprise that speeches and sermons make up a large part of the book, roughly a third of it by many estimates. The apostles had learned the message, and now they would proclaim it.
Wait for the Gift
Luke closes his introduction with a command and a promise.
Acts 1:4-5 On 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. For John baptized with water, but in a few days you will be baptized with the Holy Spirit.”
The “gift my Father promised” is the Holy Spirit. Jesus had told his disciples that it was actually good for them that he was leaving, because then the Spirit would come (John 16:7). While Jesus appeared to them from time to time during those forty days, the Spirit would be with them continually.
Luke mentions the Holy Spirit three times in these first eight verses alone, and dozens of times throughout the book. That’s why some readers have suggested that “The Acts of the Holy Spirit” would be an even better title than “The Acts of the Apostles.” The apostles were the messengers, but God was the one driving the mission.
Jesus also contrasted two baptisms. John the Baptist immersed people in water as a sign of repentance. Jesus would immerse his followers in the Spirit himself. The Greek word baptizō means to dip or immerse. The disciples would soon be completely saturated with God’s presence and power. We’ll see that promise fulfilled at Pentecost (Acts 2:1-13).
Notice too the phrase “in a few days.” Does that sound like the end of a story or the beginning? Jesus’ death and resurrection weren’t the final chapter. They were the start of something new.
What This Means for Us
Acts is the story of ordinary people who didn’t just learn about Jesus. They acted on what they learned. It’s easy to reduce faith to intellectual agreement, church attendance, or the occasional Bible reading. Those things are good, but Luke didn’t stop at his Gospel. He kept writing, because the story of Jesus is meant to keep moving through his people.
That story still isn’t finished. Somebody once shared the message of Jesus with you. The question Acts puts in front of every believer is simple: what will you do with it? The same Spirit who empowered the first disciples lives in every follower of Jesus today. In the next lesson, Jesus explains what that power is for (Acts 1:6-11).
The Takeaway
Why did Luke write the book of Acts? To show that Jesus’ story didn’t end with the resurrection. After forty days of convincing proofs and kingdom teaching, Jesus promised his followers the Holy Spirit. Acts tells how ordinary believers, empowered by the Spirit, acted on Jesus’ message and carried it to the world. Christianity is more than an idea. It’s a message to live out.
