What does Acts 21:22 mean?

The elders of the church in Jerusalem are in a bind. A large contingent of their church is composed of Jewish Pharisees—a group prone to over-emphasize the Mosaic law and make up new rules when they feel the Law isn't enough. Unlike the Sadducees, who stick to the Law as written but enjoy the cultural and financial advantages of the Roman Empire, the people like the Pharisees and look up to them.

Paul was in training to be a Pharisee when he met Jesus far away on the road to Damascus (Acts 22:3; 9:3–4). Since then, he has spread Jesus' message to Gentiles in modern-day Turkey, the island of Cyprus, Greece, and Macedonia. He has already had run-ins with Pharisee-Christians who tried to convince Gentile Christians they had to follow the Mosaic law, as well. After a great debate, the apostles met with the pastor and elders of the church in Jerusalem and decided the Gentiles only needed to refrain from sexual immorality, food that had been sacrificed to idols, and eating blood (Acts 15:1–21).

Somehow, the Pharisaical Christians in Jerusalem heard that Paul was telling Jewish Christians they shouldn't circumcise their sons or eat a kosher diet. This rumor is, of course, not true. In fact, Paul circumcised Timothy because he was Jewish (Acts 16:1–3). When Paul was out in the field, the Jerusalem church didn't have to worry directly about his teachings. Now he's back.

But Paul's not alone. He's come with several representatives who have brought donations from their predominantly-Gentile churches for the church in Jerusalem (Acts 20:4; Romans 15:26). What if the Pharisees think it's a bribe to entice the elders to lighten restrictions on Jewish and Gentile believers?

From a practical standpoint, Paul is more "expendable" than the Pharisees in the Jerusalem church. That is, to lose the support of that group would be a tragic misunderstanding and a major blow to evangelism in the city. So, the elders make Paul fix the problem. As it happens, a group of men need to finish the rites of their Nazirite vow. If Paul acts as their sponsor, it should clarify that he still values Judaism. Paul agrees, but before he can fully complete the rite he is falsely accused of bringing one of those Gentile gift-bearers into the temple; a riot erupts and Paul gets arrested (Acts 21:23–36).