Certain individuals decided to add to the message of the gospel and teach that Gentiles should first become Jews before they could be saved. They required them to be circumcised according to the law of Moses (15:1).
That greatly disturbed Paul and Barnabas who had been entrusted with, and had declared the message to Gentiles (and Jews) since they departed after their commissioning at Antioch.
After rejection by Jews, they went to Iconium where both Jews and Greeks became believers. There, it was unbelieving Jews who tried to poison the minds of believers and set them against Paul and Barnabas. They fled to Lystra and Derbe,
After the miraculous healing of a crippled man, the Gentiles actually believed that Paul and Barnabas were the gods Zeus and Hermes, but the apostles instructed them about the God who made heaven and earth.
Again, Jews came from Antioch and Iconium to stir up trouble, stoning Paul. But even through persecution they fulfilled their commission and brought back good news to Antioch that God “had opened a door of faith for the Gentiles.”
That should have been cause for celebration but instead, some partisan “believers” came with this teaching about circumcision.
They seemed to ignore what God had done abolishing distinction between Jews and Gentiles by bringing both to faith and removing the dividing wall.
Love, like death, hath all destroyed
Rendered all distinctions void;
Names, and sects, and parties fall:
Thou, O Christ, art all in all.
Charles Wesley, 1797-88