Now, the request of Paul’s Jerusalem leaders was a reasonable one. They didn’t ask Paul to do something that was contrary to his faith or practice. In fact, they didn’t ask Paul to do something he wasn’t already doing on his own. We simply need to remember what Luke told us in chapter 18:
Paul, after staying many more days in Corinth, said farewell to the brothers and sailed away to Syria accompanied by Priscilla and Aquila. He had his hair cut off at Cenchrea because he had made a vow —Acts 18:18
Later in chapter 20, we read:
For Paul had decided to sail past Ephesus so as not to spend time in the province of Asia, for he was hurrying to arrive in Jerusalem, if possible, by the day of Pentecost —Acts 20:16
What is significant in that last verse is that Paul was still celebrating the prescribed feasts. This one being Shavu’ot, also called the Feast of Weeks. We know this one as Pentecost, and Shavu’ot is one of the four feasts men were required to journey to the Temple to celebrate. What this is telling us is that Paul continued to worship as a Jew. And that the request of his brethren in Jerusalem was merely a petition to make his practice public enough to dispel any false information circulating about him. This was for the good of everyone.
The Jerusalem church leaders also made it very clear to Paul that their request was in no way to be understood as contradictory to their previous decision at the Jerusalem Council:
. . . regarding the Gentiles who have believed, we have written a letter, having decided that they should avoid meat that has been sacrificed to idols and blood and what has been strangled and sexual immorality” —Acts 21:25
Now why they brought this up? I don’t know, because Paul was one of those who delivered the letter, but the relationship between Jewish Christians and Gentile Christians needed clarification. The first step had been taken at the Jerusalem Council. And these are essentially the same men who decided that Gentiles don’t need to convert to Judaism in order to be saved. That decision is reaffirmed by the Jerusalem church leaders here in this chapter.
Now, in the light of charges that Paul taught Jewish Christians (living abroad in Gentile territory) to forsake their Jewish culture and traditions, the Jerusalem church leaders deal with the other side of the equation: Jewish converts don’t need to forsake their Jewish heritage because they have become Christians. Some have objected, based on the false assumption that to continue to observe certain Jewish ceremonies (for example, to celebrate the feasts) was to deny the person and the work of Jesus Christ. Now remember that these same Jewish rituals were, as Paul wrote elsewhere, “. . . only the shadow of the things to come, but the reality is Christ!.” So, a believing Jew could now celebrate Shavu’ot (for instance), seeing its fulfillment in the sacrificial death of Christ. Temple worship during the Millennium (as described in Ezekiel 40) appears to do the same thing. Celebrating Old Testament ceremonies as having been fulfilled in Christ is legitimate; observing Old Testament rituals instead of Christ is quite another matter.
If interested, you can download the entire study of The Story of Acts