Galatians 1:9
As we said before, so say I now again, if any man preach any other gospel unto you than that ye have received, let him be accursed.
Galatians 2:14
But when I saw that they walked not uprightly according to the truth of the gospel, I said unto Peter before them all, If thou, being a Jew, livest after the manner of Gentiles, and not as do the Jews, why compellest thou the Gentiles to live as do the Jews?