As the gospel spread beyond the Jewish world, a sharp question arose: must Gentile converts be circumcised and keep the Law of Moses to be saved? Some insisted they must. Paul and Barnabas, who had seen the Spirit poured out on uncircumcised Gentiles, insisted otherwise. The matter was brought to Jerusalem.
Acts 15 records the gathering of the apostles and elders. Peter testified that God had made no distinction, cleansing Gentile hearts by faith. James, presiding, proposed the resolution: the Gentiles were not to be burdened with the Law, but asked to abstain from a few practices for the sake of fellowship.
The Council of Jerusalem is the first council of the Church and the pattern for every council after it: a question that threatened the gospel, brought before the gathered leaders, answered from Scripture and the witness of the Spirit. Its decision — that salvation is by grace, not by the Law — opened the Church to the nations.