Galatians 1:9

1:9 As we have said before, and now I say again, if any one is preaching to you a gospel contrary to what you received, let him be condemned to hell!

Galatians 2:4

2:4 Now this matter arose because of the false brothers with false pretenses who slipped in unnoticed to spy on our freedom that we have in Christ Jesus, to make us slaves.