As we have already said, so now I say again: If anybody is preaching to you a gospel other than what you accepted, let that person be under God's curse! (NIV)
As we said before, so I now say again: If anyone is preaching to you a gospel different from or contrary to that which you received [from us], let him be accursed (anathema, devoted to destruction, doomed to eternal punishment)! (AMP)
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. (KJV)