Galatians 1:6-9 I marvel that you are turning away so soon from Him who called you in the grace of Christ, to a different gospel, which is not another; but there are some who trouble you and want to pervert the gospel of Christ. But even if we, or an angel from heaven, preach any other gospel to you than what we have preached to you, let him be accursed. As we have said before, so now I say again, if anyone preaches any other gospel to you than what you have received, let him be accursed.
Haggai 2:12-13 "If one carries holy meat in the fold of his garment, and with the edge he touches bread or stew, wine or oil, or any food, will it become holy?""" Then the priests answered and said, "No." And Haggai said, "If one who is unclean because of a dead body touches any of these, will it be unclean?" So the priests answered and said, "It shall be unclean."
Romans 16:17-18 Now I urge you, brethren, note those who cause divisions and offenses, contrary to the doctrine which you learned, and avoid them. For those who are such do not serve our Lord Jesus Christ, but their own belly, and by smooth words and flattering speech deceive the hearts of the simple.
Ephesians 4:14 that we should no longer be children, tossed to and fro and carried about with every wind of doctrine, by the trickery of men, in the cunning craftiness of deceitful plotting,
2 Timothy 2:15 Be diligent to present yourself approved to God, a worker who does not need to be ashamed, rightly dividing the word of truth.
2 Timothy 3:13 But evil men and impostors will grow worse and worse, deceiving and being deceived.
1 John 4:1 Beloved, do not believe every spirit, but test the spirits, whether they are of God; because many false prophets have gone out into the world.
1 John 4:5-6 They are of the world. Therefore they speak as of the world, and the world hears them. We are of God. He who knows God hears us; he who is not of God does not hear us. By this we know the spirit of truth and the spirit of error.