Galatians 1:8, 9
Galatians 1:8 ESV
But even if we or an angel from heaven should preach to you a gospel contrary to the one we preached to you, let him be accursed.
Galatians 1:9 ESV
As we have said before, so now I say again: If anyone is preaching to you a gospel contrary to the one you received, let him be accursed.