Traditionally, the theme of the book of Acts is the story of the unfolding of Acts 1:8. "You will receive power when the Holy Spirit comes upon you; and you shall be my witnesses in Jerusalem, and in all Judea, and to the ends of the earth". When we read the book of Acts this way we see the fulfillment of God's promise to the church to be a witness and to fulfill the covenant of Abraham that the church would become a blessing to all the earth. This is the actual story line and so this is the obvious approach to take. The question we then ask is, "How do we too become part of this story of mission expansion in our generation."
What jumps out to me in reading Acts is the community that that early church had and how this enabled their witness. People were fearful of the church (in awe) of them because of the things that happened in their lives. People were being healed; various ethnic groups were getting along very well (chapter 6). They shared all their meals and possessions. They worshipped daily and devoted themselves to the apostles teaching.
I have read many sermons on the book of Acts and few commentaries link the Moral Beauty of the Church Community with the power of its witness. For some reason, we think that the power of their witness was simply the miracles. But we need to take a more Kingdom approach.
The kingdom of God was in full expression in the early church. The kingdom in the church age is heaven on earth + persecution and suffering. There will be a day when the kingdom will come in fullness and the kingdom will be heaven on earth -the suffering and persecution and tribulations of this age.
Romans 14:7 says "the kingdom of God is righteousness, peace and joy in the Holy Spirit". This "kingdom experience" is what the early church had in such power. The quality of life was filled with such a high degree of purpose and righteous relationships (community) that they had a great degree of moral distinction from the world around them. This connection of the "Kingdom quality of life" and the explosive expansion of the church is the key message of ACTS. In fact, this is the point Luke is making.
In the early historical setting, the church was being persecuted and the political people who were persecuting the church had spread amazing rumors about the church. The rumor was that they were cannibals because they "ate the body and drank the blood of Christ". They were blamed for political revolt because they refused to worship the emperor. (Much like Daniel). So Luke is saying, "No here is the real story of the inner life of the church". He shows us the utopian world of the early church. He shows us the incredible humility of Peter. Peter was a great delegater of power. Peter was courageous. Luke's overall theme is actually that the church was a beautiful people worthy of great honor. Do not believe the lies you have been hearing from those who weren't there.
The key to the book of Acts is to see the story of a Morally Beautiful Community and how these qualities which come from the Holy Spirit create the powerful witness that has turned the world on its head.