Acts 21 continues the narrative of Paul's journey to Jerusalem. After bidding farewell to the Ephesian elders, Paul and his companions set sail and reach Tyre, where they spend a week with the local disciples. The disciples warn Paul through the Holy Spirit not to go to Jerusalem, but he remains determined. Continuing their journey, they arrive in Caesarea and stay at the house of Philip the evangelist. While there, a prophet named Agabus predicts Paul's arrest in Jerusalem, which causes the believers to plead with him not to go. However, Paul affirms his commitment to God's will.
Eventually, Paul and his companions reach Jerusalem, where they are warmly received by the brethren. However, some Jewish Christians express concern about Paul's teachings among the Gentiles and urge him to participate in a purification ritual to demonstrate his adherence to the Law of Moses. Paul agrees and takes part in the ritual.
As the chapter concludes, Paul is in the temple when Jews from Asia stir up a crowd against him, falsely accusing him of bringing Gentiles into the temple. The city becomes chaotic, and Paul is seized by the mob. The Roman commander intervenes, ordering Paul to be bound and taken to the barracks for questioning.