I love the book of Acts.
I love the way the gospel explodes out of Jerusalem. I love the way ordinary men have extraordinary courage. I love the way the Holy Spirit comes upon the Jews, upon the Samaritans, and on the Gentiles in such a way that no-one can dispute that these also are God's people, holy and precious to Him. I love the way the narrative (sorry, recount) slows down when Luke is present and we hear every tiny detail.
Most of all I love the 'purple' verses in Acts. These are the verses that I think tell us what the book is about. They are the verses where Jesus speaks. They remind us that even the book of Acts (often thought to be about the Holy Spirit more than Jesus) is His book. It is His work, His mission, His Spirit, His word, His apostles, His name, His world. As far as I can tell these are the only times the risen Jesus speaks directly in the book, though these are quoted at other times (e.g. 22:21 and 26:17 refer back to 9:15) and the apostles remember other things he said when he was with them (e.g. 11:16; 20:35).
Here they are.
7 He said to them, “It is not for you to know times or seasons that the Father has fixed by his own authority. 8 But you will receive power when the Holy Spirit has come upon you, and you will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth.”
Everyone knows about this one. Not long after this the Holy Spirit comes upon the apostles (Acts 2) and the speak of the risen Christ in Jerusalem (Chapter 3:1-6:7), throughout Judea and Samaria (6:8-8:40) and thence to the ends of the earth (Chapter 9:1-28:31). Though many object that chapters 9-28 comprise such a long section that 'to the ends of the earth' doesn't adequately explain what is going on. This is true...
15 But the Lord said to him, “Go, for he is a chosen instrument of mine to carry my name before the Gentiles and kings and the children of Israel. 16 For I will show him how much he must suffer for the sake of my name.”
At the very start of this section, Jesus speaks for the second time. He actually says quite a lot more, first to Saul (his chosen instrument) and then Ananias (to whom the above is spoken), but I think these verses are the guts of it. And this is what Saul (later to be called Paul) does. He takes the gospel to the Gentiles in his missionary journeys (13-20). It is his practise to speak first to the children of Israel where-ever he goes (e.g. 13:13-48; 17:2; 18:5-6) and does so on his return to Jerusalem (21-22). Then after his arrest there, he carries the name of Jesus before Kings (23-26). There was the Governor Felix, Governor Festus, King Agrippa, and ultimately he awaits an audience with the Emporer (27-28).
9 And the Lord said to Paul one night in a vision, “Do not be afraid, but go on speaking and do not be silent, 10 for I am with you, and no one will attack you to harm you, for I have many in this city who are my people.”
Just as Jesus said he would in 9:16, Paul suffers for the name of Christ. He has had a pretty rough time of it in his travels and it is building up to a pretty rough time in Corinth. But Jesus will have his name proclaimed in this place. Even though the Jews try to stop him, the proconsul (Gallio) is not interested in their complaints (18:12-16). Furthermore, I think the encouragement "do not be afraid, but go on speaking and do not be silent for I am with you", is fairly pertinent to the whole book.
11 The following night the Lord stood by him and said, “Take courage, for as you have testified to the facts about me in Jerusalem, so you must testify also in Rome.”
Again Paul suffers for the name of Christ. Now he is in prison in Jerusalem and Jesus speaks to him again, again a word of encouragement and again he tells Paul his plan. Just as he as carried Jesus name before the children of Israel (9:15) and testified about Jesus in Jerusalem, so also he must do so in Rome. His arrest is all part of Jesus' plan to get Paul to Rome, and he will get there: through assassination plots, through years in prison, through storm and shipwreck; the gospel must go where Jesus has said it will.