Galatians 5:2

Behold, I Paul say unto you that, if ye receive circumcision, Christ will profit you nothing.

Behold, I Paul say unto you ... Intensely personal and dramatic, this appeal was intended to affirm in the most dogmatic and positive way possible the truth which he was uttering.

Circumcision, Christ will profit you nothing ... There were exceptions to this rule, for Paul himself had been circumcised; and what is meant is "that circumcision with any view to its aiding or leading to one's justification would be a denial of Christ, a repudiation of the Christian gospel and the forsaking of Christianity." As MacKnight said, "This general expression must be limited; because we cannot suppose that the circumcision of the Jewish believers incapacitated them from being profited by Christ."[2]

The deduction is mandatory that the purpose of the Judaizers among the Galatians had made this their purpose, to circumcise the Galatians, no doubt representing to them that it was no great thing and did not involve them in the more onerous and expensive obligations of Judaism. Paul would expose the fraud in such a proposition in the very next verse.