The Acts of the Apostles

Acts, Luke’s second book, commences at the point where his first left off—the ascension of our Lord (Luke 24:51; Acts 1:9)—“The former treatise have I made, O Theophilus, of all that Jesus began both to do and teach, Until the day in which he was taken up, after that he through the Holy Ghost had given commandments unto the apostles whom he had chosen” (Acts 1:1-2).
A better title for the book would be “The Acts of the Holy Spirit”, for in it we see the practical guidance of the Holy Spirit in the lives of the apostles and the early church. A guidance that is no less real or applicable in this present day.
With the resurrection and ascension of the Lord Jesus Christ, and the Holy Spirit come down according to His promise (John 16:7), the church—the assembly of God—is formed. Prior to the day of Pentecost the church did not exist, and after the rapture the church will no longer be found on earth. These are the circumstances that give the church its true character.
Even though Acts covers little more than 30 years, it brings before us an entire outline of the history of the church.