Conflict over circumcision in Antioch
Some men came to Antioch and told the believers they needed to be circumcised. Paul and Barnabas argued with them, and went to Jerusalem to talk with the apostles.
Key passages
Ac 15:1–2

And some men came down from Judea and began teaching the brothers, “Unless you are circumcised according to the custom prescribed by Moses, you cannot be saved.” And after there was no little strife and debate by Paul and Barnabas against them, they appointed Paul and …