"But it was because of the false brethren secretly brought in, who had sneaked in to spy out our liberty which we have in Christ Jesus, in order to bring us into bondage. But we did not yield in subjection to them for even an hour, so that the truth of the gospel would remain with you. But... those who were of reputation contributed nothing to me." (Galatians 2:4-6)There will always be those who believe that it is their personal responsibility to correct and discipline the body of Christ. They see themselves as the Christian police, looking for trouble, sniffing out heresy, and making sure everyone is behaving as they ought. Unfortunately, Christianity to them means Christianity as they are doing it. Their goal is not the purity of the Gospel but your conformance to their ways and beliefs. It is not enough for them to have their own ideas and customs, you must join them and become like them. In their mind, apart from them, there is no salvation.
This is what was happening in the church when Paul, Barnabas, and team went to Jerusalem to see Peter, James, and John. There were those of the circumcision who held to the belief that, unless you were circumcised, you could not be saved. It is understandable how they could believe this. All their lives they grew up believing that circumcision was the mark of true religion and those who were not circumcised did not belong to the people of God. In their zeal, they would secretly join churches to subvert them and to bring them back into conformance with the Jewish law. They were likes spies who came in looking for those who believed differently and then coercing, or forcing, them into compliance.
We must always be aware, even today, that there are people who will want to get to know us so that they might change us and make us like them. If you doubt this, simply try starting a church and you will get all those people who believe they know how to run a church and who want to mold the new enterprise after themselves. Paul wrote of such people saying, "They eagerly seek you, not commendably, but they wish to shut you out so that you will seek them." (Galatians 4:17) We must be careful to identify those who want relationships with us from those who want something from us. These false brethren want our conformance and our agreement, but they really do not want us. They want our conformance so that they might seem to be right. Paul writes of them, "Those who desire to make a good showing in the flesh try to compel you to be circumcised, simply so that they will not be persecuted for the cross of Christ." (Galatians 6:12)
Fortunately, Paul did not yield to them, neither did the Apostles back in Jerusalem. The church rejected their attempts to re-enslave us to works and to law, and so should we too. We must not yield to those who seek to draw us away from the true Gospel; from grace, love, and forgiveness. We must continue in resolve to remain free and to be free in our relationships with other brothers and sisters in Christ. When others come to corrupt the Gospel with their subterfuge, we must not yield to them but reject their efforts them and leave their influences behind.