There were several Jews in the Early Church, who had received Jesus as their Lord and Savior. Of course, all Jews were circumcised when born, but Gentiles were not. Some of the more legalistic Jews - the Judaizers - insisted that only Jews could become Christians and so any Gentile wishing to be saved must first also be circumcised and become a Jew. Even today there are Christians who try to come back to Jewish practices, believing that you aren't completely a Christian without it. This is simply not true. The Judaizers charged Paul of preaching a fake gospel, but they were the ones preaching a fake gospel. Paul calls these men "false brethren". The best thing was that they had a high esteem for the Law and the Scriptures and God's choice of the Jews as His chosen people. Their concern was that His commands might be overlooked or broken. However, they proceeded to add their own human conventions and standards to God's Law and they also ignored the fact that God's promises are to all nations!
Rodney Howard Browne explains that a non secular spirit is always judgmental and feels compelled to stuff everyone into the same mold. Because these men were perverting the gospel, Paul did not give them a chance to air their views. They weren't curious about the truth - all they wished to do was disagree - but Paul refused to be dragged into a fight.
Rodney Howard Browne points that Paul had been even more legalistic than they and had been set free and brought into the liberty of deliverance thru Jesus Christ. He knew all their viewpoints and he knew they were wrong. There was nothing else to discuss.
The Judaizers charged Paul of perverting the truth, but he had received his message from Christ Himself. Galatians 1:10-12 ( KJV ) asserts, "For do I now convince men, or God? or do I try to please men? for if I yet pleased men, I shouldn't be the servant of Christ. Eleven But I certify you, brethren, that the gospel which was preached of me isn't after man. Twelve For I neither received it of man, neither was I taught it, but by the revelation of Jesus Christ."
"The Judaizers related that Paul was a traitor to the Jewish religion, but he had been more advanced in Judaism than almost all of his contemporaries and more enthusiastic for the traditions of his fathers' than any of them, until his face-off with Jesus on the Damascus road. For the 1st time, Paul experienced God's grace and was totally set free. The change was so great that God even changed his name! He was now as enthusiastic for the Gospel as he formerly was for the Law - yet with no malice!" (Galatians 1:13-17)
"The Judaizers said Paul compromised and preached a watered down message to the Gentiles, but he had met privately with the other apostles and they, themselves, had declared that the message Paul preached was indeed the true Gospel. Not that he required their approval because he had God's approval, but out of courtesy, he had a meeting with them. In talking to Paul, the apostles realized that God had indeed called him to evangelise the Gospel to the Gentiles and gave him and Barnabas the right hand of fellowship. They only asked one thing of him : that he would remember the poor, which he was raring to do."
(Galatians 2:6-10)
The Judaizers said Paul was disregarding the Law of Moses; however, all he did was to put the law in its proper place. the Law was given to show people where they have sinned and it points them to their need for a Savior - Jesus Christ.
If you are Christ's, then you are Abraham's seed, and heirs according to the promise!