Coming World War 3
Act 15:1 And certain men came down from Judea and taught the brethren, "Unless you are circumcised according to the custom of Moses, you cannot be saved."
God called Paul (Saul) of Tarsus a devout Jew to be the Apostle to the Gentiles. He was bold, fearless and faithful to God's words. He showed extreme zeal in his mission to arrest Christians, whom the Jewish leadership considered as deviant or heretical.
Immediately after his conversion, he went to Arabia where Jesus Himself taught everything needed for him to make disciples for Jesus.
Having known that salvation is by grace for both Jews and Gentiles, he stood firm on the word of God. He rejected the command from the apostles in Jerusalem to circumcise these new Gentile converts.
Act 15:2 Therefore, when Paul and Barnabas had no small dissension and dispute with them, they determined that Paul and Barnabas and certain others of them should go up to Jerusalem, to the apostles and elders, about this question.
At the Jerusalem Council
Act 15:5 But some of the sect of the Pharisees who believed rose up, saying, "It is necessary to circumcise them, and to command them to keep the law of Moses."
Paul kept his peace during the whole meeting, allowing God to deliver His judgment, which every Christian must abide by.
Peter's Testimonies
Act 15:7,10-11 And when there had been much dispute, Peter rose up and said to them: "Men and brethren, you know that a good while ago God chose among us, that by my mouth the Gentiles should hear the word of the gospel and believe. Now, therefore, why do you test God by putting a yoke on the neck of the disciples which neither our fathers nor we were able to bear? But we believe that through the grace of the Lord Jesus Christ we shall be saved in the same manner as they."
Peter's testimonies convicted those who have not been delivered from Judaism. It also reminded them that God is faithful to His words.
Act 15:12 Then all the multitude kept silent and listened to Barnabas and Paul declaring how many miracles and wonders God had worked through them among the Gentiles.
Condemnation of Judaizers
Act 15:19 Therefore I judge that we should not trouble those from among the Gentiles who are turning to God, but that we write to them to abstain from things polluted by idols, from sexual immorality, from things strangled, and from blood.
Adding Jewish laws, feasts, beliefs, culture, practices, etc. to the grace of God in Christ Jesus are the Judaizers. They have fallen from grace and await damnation. Today, Judaizers are practiced in the Hebrew Roots Movement, which has rebelled against Jerusalem Council's command given by God.
Gal 5:4 You have become estranged from Christ, you who attempt to be justified by law; you have fallen from grace.