The Gospel has been preached in Jerusalem, in Judea and in Samaria with dramatic results. People are choosing to follow Christ by the hundreds and thousands. But, with the exception of the Ethiopian in Chapter 8, the Gospel has not yet intentionally crossed the Semitic world for the Gentile world. This changes in Chapter 10. Peter, the first of the Apostles, while residing in a town called Joppa (near modern day Tel Aviv) has a vision, it is a confusing vision. Peter has worked hard to keep Kosher and to be a faithful Jew. In this vision he is told to kill and eat animals and reptiles that are unclean. When he refuses he is told "what God has made clean you may not call unclean.". Simultaneously there is a Roman Centurion named Cornelius who lives in Caesarea by the Sea (about 12 miles away). Cornelius has a vision of an angel and the angel tells him he has found favor and he is to send to Joppa for Peter and to do what he says. Cornelius being a man of action immediately sends soldiers to Joppa to bring Peter back. The soldiers arrive in Joppa the moment Peter's vision is concluding. Peter, rightly, takes this a sign from God, and in the morning allows himself to be taken to Caesarea by the Sea.
Peter and Cornelius exchange stories. In preparation for his arrival Cornelius has assembled his family and all of his closest friends to hear this man named Peter. Peter begins "I truly understand that God shows no partiality . . ." He preaches, what I believe is his shortest recorded sermon, and after telling the Romans assembled about the forgiveness found in Jesus . . . the Holy Spirit shows up and lives are transformed. Peter orders them to be taken to water and they are all baptized. Peter stays for several days, teaching, and telling the stories of Jesus.
This sovereign act of God, the sending of the Holy Spirit, in a kind of Gentile Pentecost becomes the irrefutable proof that God sent Jesus for all the world (and not just a select few). Jew and Gentile, slave or free, male or female . . . The Holy Spirit was falling on all who would receive the good news of the Kingdom of God. This is one of those significant historical turning points that turns the Christian movement from a minor sect of Judaism into a global, universal movement.