What does Acts 28:23 mean?
The Jewish leaders in Rome have agreed to visit Paul. They are open to hearing about the sect of Jesus-worshippers. They have very little knowledge other than "everywhere it is spoken against" (Acts 28:22). They've heard next to nothing about Paul, and he's already explained that he may be under house arrest, but he's innocent of all charges (Acts 28:17–21). At least they're willing to listen.This is Paul's modus operandi in every new town he enters. Ideally, he'd go to the synagogue and speak there, but that's not possible in this case. Luke rarely dictates Paul's messages. In Athens, Paul identified their unknown god with Jesus (Acts 17:22–31). To the crowd in Jerusalem after he was arrested, he gave his testimony (Acts 22:3–21). In this case, we can assume Paul's message is very similar to the one he gave in Antioch in Pisidia (Acts 13:16–41).
Paul's explanation about the kingdom of God is important. To the Jews, it includes the fulfillment of the Abrahamic and Davidic covenants when Jews will be blessed above all other nations. Paul needs to explain that a large factor is the part of the Abrahamic covenant where Jews bless the world (Genesis 22:18). This blessing is Jesus, a Jew, providing salvation to all who will believe (Galatians 3:16, 22, 25–29).
The Jews react the same as those in all cities Paul visits: some believe and accept Jesus as their Messiah and some don't. Paul knows that God interacts with the Jewish nation as a group, and this split frustrates him (Acts 28:24–31). It means individual Jews will join the church, but the nation will not be the driving force of bringing Gentiles to Christ. This is why Jesus chose Paul to reach the Gentiles (Acts 9:15).
In Acts 28:17–29 Paul finally receives his heart's desire: to witness to the Jews in Rome. Rome is a strategic city and if the Jews there accept Jesus as their Messiah, they will legitimize Jesus-worship to the other Jews in the Empire. As in every city Paul visits, however, some accept Jesus and others don't. Paul becomes frustrated and redoubles his efforts to reach the Gentiles. He spends two years under house arrest but with the freedom to write and to speak with whomever chooses to come through his door.
Acts 28 records Paul's three-month stay on the island of Malta and two-year house arrest in Rome. On Malta, God empowers Paul to perform healing miracles which endear him to the locals. Once he reaches the shores of Italy, many other believers accompany him on his last leg to Rome. In Rome, he finds the Jews just as accepting of Jesus as elsewhere; some believe, but many don't. Paul reaffirms his mission to the Gentiles and spends his time preaching while under house arrest.