Experiencing God’s protection in travels once again (Acts 27:1–28:16), Paul arrived in Rome and spoke before the Jewish leaders and a larger group of Jews as well (Acts 28:17–31). Paul’s final words and actions in Acts indicated that the witness to Christ would continue yet further. The Gentiles would hear the gospel, which kept Paul preaching it to all who listened (cf. Acts 28:28–31).
The words of Jesus in Acts 1:8 announce where the witnesses of Jesus and His resurrection would go—to Jerusalem, Judea and Samaria, and the end of the earth. Acts 1–7 records the witness to Jerusalem, Acts 8 the witness to Judea and Samaria (cf. Acts 8:1, 14), and Acts 9–28 the witness to the end of the earth.
Looking at Acts 9–28 more closely, we see a progression of this witness moving further and further away from Jerusalem. Saul (Paul) is called to be an apostle to the Gentiles in Acts 9. Peter takes the gospel to the Gentile Cornelius in Caesarea in Acts 10. Peter reports back to Jerusalem in Acts 11 to confirm that God is saving the Gentiles. Then, the church is relieved from persecution through the death of Herod in Acts 12.