what was the dispute between the Jerusalem believers and the Gentile converts at Antioch?
The dispute at Antioch centered on whether Gentile converts needed circumcision and Law-keeping for salvation. Jerusalem Jewish believers, including believing Pharisees, argued that faith in Christ was not enough alone; Gentiles had to be circumcised and commanded to keep the Law. Paul's faith-alone Gospel for Gentiles was the bone of contention.
Les explains that the Jerusalem believers, specifically believing Pharisees who had embraced Jesus as Messiah, insisted Gentile converts must be circumcised and keep the Law. They said faith alone was insufficient for salvation. This was the bone of contention between the Jerusalem Jewish believers and the Gentile converts Paul had won in Antioch. Les sees the same demand today: believe the Gospel, but add Law-keeping.
And the apostles and elders came together for to consider of this matter.