This chapter of the book of events is a theological milestone in the histopia of Christianity, the main leaders of the early church agree to meet in Jerusalem to solve the situation arising between the legalism of Jewish Christians and the newly converted Gentiles.
Remember that the legalists, called Judaizers, believed a lot in rituals, specifically in circumcision, despite having faith in Jesus.
From that agreement, the Jerusalem Council sanctioned what had become the doctrinal foundation of the Christian faith: salvation is by grace and only through faith.
So the clarification of salvation by grace through faith in Jesus Christ alone also led to the definitive break between Judaism and Christianity.