Some Jewish believers said that God will save only people who are circumcised.

Acts 15:1-2

15 Then some Jewish believers went down from Judea province to Antioch. They started teaching the non-Jewish believers there, and said, “You ◄must be circumcised/must have God’s mark put on you► to indicate you belong to God, as Moses commanded in the laws that he received from God. If you do not do that, you will not be saved {God will not save you}.” 2 Paul and Barnabas strongly disagreed with those Jews and started arguing with them. So the believers at Antioch appointed Paul and Barnabas and some of the other believers to go to Jerusalem, in order that they would/could discuss this matter with the apostles and other spiritual leaders.