Galatians 2:4-5

Galatians 2:4 introduces another reason Paul went up to Jerusalem (Galatians 2:1). Evidently representatives of the false teachers (counterfeit Christians) had entered Paul’s arena of ministry representing themselves as true Christians. But they had opposed what Paul had taught. Their intent was to bring Paul and all other preachers and hearers of the true gospel into bondage by imposing circumcision as a condition for salvation. They were not successful. The truth of the gospel means "the gospel in its integrity . . . the doctrine of grace." [Note: Lightfoot, p. 107.] The liberty to which Paul referred is not freedom in the abstract, but a liberty that believers have in Christ Jesus. [Note: Morris, p. 69.]

"It thus emerges that the interlopers were sham-Christians precisely because they had not really grasped the fundamental principle of the gospel-justification by faith apart from works of the law." [Note: Fung, p. 94.]