Acts 21:20

And when they heard it, they glorified the Lord, and said unto him, Thou seest, brother, how many thousands of Jews there are which believe; and they are all zealous of the law:

The day after Paul arrived in Jerusalem, he went with his companions to James, where all the elders were present, following the glad reception given him by the brethren on his arrival. Although the brethren received him gladly, and although he everywhere found hearts open to receive the glad tidings and loving him for Christ and the truth, prejudice and envy and jealousy also existed alongside that love. That kindly greeting could not remove his anxiety about the attitude of the church at Jerusalem toward himself and his work, whose real feelings would be more fully seen in that meeting with the elders.

At the meeting Paul declared particularly what God had wrought among the Gentiles by his ministry, and he and his companions presented contributions from the Gentile churches for the poor Jewish believers. Those gifts represented sacrifice and loyalty to God's work and brotherly love, yet some of the leaders present could not appreciate the love that had prompted them. Hearing the report led them to glorify the Lord in praise for the wonders of His grace, expressed at the close of Paul's address in a season of solemn praise where many voices swelled the Amen in hearty sanction of his work. The Spirit of God impressed their minds and affected their hearts, the tidings of the progress of the gospel and the evidence that God's power was working with his efforts softened their feelings toward Paul, and the report with the gifts convinced them and even doubters that their prejudice was unfounded, that his ministry had heaven's approval, and that the new churches were faithful.

The report brought the Jewish leaders to recognize that they had been wrong to impose Jewish customs and traditions as controls on the work. That course had hindered the gospel because they had failed to recognize that Christ's death had broken down the barrier between Jews and Gentiles. At the same time many thousands of Jews in Jerusalem believed in Christ yet remained zealous for the law, and their attachment to the law left them vulnerable to false reports about Paul and to pressure for concessions concerning Jewish customs. Some were not ready to accept the council's decision about Jewish customs and viewed Paul with jealousy, thinking his teaching weakened the ceremonial law.

Those zealous believers had been informed that Paul taught the Jews among the Gentiles to forsake Moses, not to circumcise their children nor to walk after the customs, so the leaders treated it as certain that the multitude must come together when they heard he had come. Answering Paul's account by pointing to the thousands zealous of the law, the leading men threw the burden wholly on him to remove the misapprehension and held him responsible for the existing prejudice and jealousy as though he gave cause for it. Instead of confessing their own wrong in letting his enemies influence them, and instead of standing in his defense before the disaffected to show them their error, they left the vindication to him. They counseled him to take the four men who had a vow, purify himself with them, and be at charges with them for shaving their heads, so all might know the reports were nothing and that he himself walked orderly and kept the law, while Gentile believers need observe no such thing except keeping from things offered to idols and from blood and from strangled meat and from fornication.