From the very beginning, Paul was warned by the Holy Spirit not to go to Jerusalem (see chapters 20:23; 21:4; 21:10,11). Luke had also asked him not to go (Luke 21:12). It was settled in Paul's mind, though, that even if it meant death, he would make the journey to Jerusalem.
The Jews in Jerusalem hated him; and, after he had been there for just a short time, they recognized him and began to yell at him, and a mob attacked him like a pack of wild dogs. It is ironic that on the same stairway to the Roman castle where Pilate had condemned Jesus to death 28 years before, Paul was given the opportunity to make a speech to the mob. This speech was Paul's testimony of how Christ had appeared to him on the road to Damascus and how he had been saved from being the chief persecutor of the Christians to a preacher of the Gospel.
Acts 20:21 records these words: "Testifying both to the Jews, and also to the Greeks, repentance toward God, and faith toward our Lord Jesus Christ." This verse explains so explicitly the two points of salvation. One is repentance (Luke 13:5); the other is faith toward our Lord Jesus Christ (Ephesians 2:8,9). Without repentance, Jesus says we should all likewise perish, and without faith it is impossible to please God.
Chapter 21 records Paul's return to Jerusalem. One purpose for the journey was to deliver the offerings which he had gathered from Gentile churches in Greece and Asia Minor for the poor saints in Jerusalem. It was a great offering, for Paul had spent over a year in gathering it. Again, we see the spirit of brotherly kindness as the offering is given from the Gentile churches to the church at Jerusalem.
