"I am astonished that you are so quickly deserting the one who called you in the grace of Christ and are turning to a different gospel-- not that there is another gospel, but there are some who are confusing you and want to pervert the gospel of Christ. But even if we or an angel from heaven should proclaim to you a gospel contrary to what we proclaimed to you, let that on be accursed! As we have said before, so now I repeat, if anyone proclaims to you a gospel contrary to what you received, let that one be accursed!"
-Galatians 1:6-9 (NIV)