Since the book of Acts focuses on God's work through the church, an informative homiletic approach would be to preach a series of sermons on the churches of the book of Acts. After carefully describing the characteristics of the churches of Acts, you would then apply these characteristics to the church today.
You could preach a series with the following messages: "The Church at Jerusalem" (Acts 2); "The Church at Antioch" (Acts 11:19-30); "The Church at Philippi" (Acts 16); "The Church at Thessalonica" (Acts 17); "The Church at Berea" (Acts 17:10-14); and "The Church at Corinth" (Acts 18:1-17).http://www.preaching.com/sermons/11567240
As an example, you might preach a sermon on the church at Antioch entitled, "The Church of the New Age." Using the text of Acts 11:19-30, develop the following outline:
1. The church at Antioch was evangelistic in nature, 11:19-21. These Christians at Antioch understood their primary purpose to be sharing the message of Christ.
2. The church at Antioch was sound in doctrine, 11:26. Barnabas and Paul spent more than a year explaining the basics of the Christian faith. The church was not just interested in making converts. They wanted to make disciples.
3. The church at Antioch was bold in character, 11:26. The followers of Jesus were called Christians, belonging to the part of Christ, because of the boldness of their commitment. They lived their lives in such a way that others could tell they belonged to the party of Christ.
4. The church at Antioch was caring in attitude, 11:27-30. They responded to the prophet's announcement of a famine in Judea by giving generously of their own resources to meet that need.
5. The church at Antioch was missionary in spirit, 13:1-4. The full story of the church at Antioch is not told until we trace the missionary journeys of Paul, for it was out of this church that Paul was sent. The church at Antioch was a church with the world on its heart.
These churches of Acts were not perfect. They were like our churches today. They had their flaws and their conflicts. And each was unique. The Jerusalem church was conservative while the Antioch church was progressive. The Philippian church was warm-hearted while the Thessalonican church was impractical. Yet these churches were a vital part of the inauguration of the Christian faith. Understanding the dynamics of these churches can be informative for us today.