In my first book, Theophilus, I wrote about what Jesus began to do and teach. This included everything from the beginning [of his life]
until the day he was taken to heaven. Before he was taken to heaven, he gave instructions through the Holy Spirit to the apostles, whom he had chosen.
After his death Jesus showed the apostles a lot of convincing evidence that he was alive. For 40 days he appeared to them and talked with them about the kingdom of God.
Once, while he was meeting with them, he ordered them not to leave Jerusalem but to wait there for what the Father had promised. Jesus said to them, "I've told you what the Father promises:
John baptized with water, but in a few days you will be baptized with the Holy Spirit."
So when the apostles came together, they asked him, "Lord, is this the time when you're going to restore the kingdom to Israel?"