A theme of Acts chapters 1 and 2 is power for witness. A key verse is Acts 1:8. The world should be able to look at the Church and see a glimpse of the future age. The same power that was given to OT prophets is given to us to spread the Gospel. Prayer before the outpouring of the Spirit is a common theme in Luke and Acts and is important for us to remember today. We need the Spirit for conversion and for empowerment. Peter preaches a sermon. The community of believers changed the way they lived because of their faith.