2 Peter 2:1: 1But false prophets also arose among the people, just as there will also be false teachers among you, who will secretly introduce destructive heresies, even denying the Master who bought them, bringing swift destruction upon themselves.

2 Corinthians 11:12-15: 12But what I am doing I will continue to do, so that I may cut off opportunity from those who desire an opportunity to be regarded just as we are in the matter about which they are boasting. 13For such men are false apostles, deceitful workers, disguising themselves as apostles of Christ. 14No wonder, for even Satan disguises himself as an angel of light. 15Therefore it is not surprising if his servants also disguise themselves as servants of righteousness, whose end will be according to their deeds.

Matthew 7:15: 15Beware of the false prophets, who come to you in sheep’s clothing, but inwardly are ravenous wolves.

1 John 4:1: 1Beloved, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world. 2By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God; 3and every spirit that does not confess Jesus is not from God; this is the spirit of the antichrist, of which you have heard that it is coming, and now it is already in the world.

Revelation 2:2: 2I know your deeds and your toil and perseverance, and that you cannot tolerate evil men, and you put to the test those who call themselves apostles, and they are not, and you found them to be false;

1 John 4:2,3: 2By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God; 3and every spirit that does not confess Jesus is not from God; this is the spirit of the antichrist, of which you have heard that it is coming, and now it is already in the world.

Matthew 7:16-20: 16You will know them by their fruits. Grapes are not gathered from thorn bushes nor figs from thistles, are they? 17So every good tree bears good fruit, but the bad tree bears bad fruit. 18A good tree cannot produce bad fruit, nor can a bad tree produce good fruit. 19Every tree that does not bear good fruit is cut down and thrown into the fire. 20So then, you will know them by their fruits.

Jude 1:3-23: 3Beloved, while I was making every effort to write you about our common salvation, I felt the necessity to write to you appealing that you contend earnestly for the faith which was once for all handed down to the saints. 4For certain persons have crept in unnoticed, those who were long beforehand marked out for this condemnation, ungodly persons who turn the grace of our God into licentiousness and deny our only Master and Lord, Jesus Christ.

5Now I desire to remind you, though you know all things once for all, that the Lord, after saving a people out of the land of Egypt, subsequently destroyed those who did not believe. 6And angels who did not keep their own domain, but abandoned their proper abode, He has kept in eternal bonds under darkness for the judgment of the great day, 7just as Sodom and Gomorrah and the cities around them, since they in the same way as these indulged in gross immorality and went after strange flesh, are exhibited as an example in undergoing the punishment of eternal fire.

8Yet in the same way these men, also by dreaming, defile the flesh, and reject authority, and revile angelic majesties. 9But Michael the archangel, when he disputed with the devil and argued about the body of Moses, did not dare pronounce against him a railing judgment, but said, “The Lord rebuke you!” 10But these men revile the things which they do not understand; and the things which they know by instinct, like unreasoning animals, by these things they are destroyed. 11Woe to them! For they have gone the way of Cain, and for pay they have rushed headlong into the error of Balaam, and perished in the rebellion of Korah. 12These are the men who are hidden reefs in your love feasts when they feast with you without fear, caring for themselves; clouds without water, carried along by winds; autumn trees without fruit, doubly dead, uprooted; 13wild waves of the sea, casting up their own shame like foam; wandering stars, for whom the black darkness has been reserved forever.

14It was also about these men that Enoch, in the seventh generation from Adam, prophesied, saying, “Behold, the Lord came with many thousands of His holy ones, 15to execute judgment upon all, and to convict all the ungodly of all their ungodly deeds which they have done in an ungodly way, and of all the harsh things which ungodly sinners have spoken against Him.” 16These are grumblers, finding fault, following after their own lusts; they speak arrogantly, flattering people for the sake of gaining an advantage.

17But you, beloved, ought to remember the words that were spoken beforehand by the apostles of our Lord Jesus Christ, 18that they were saying to you, “In the last time there will be mockers, following after their own ungodly lusts.” 19These are the ones who cause divisions, worldly-minded, devoid of the Spirit. 20But you, beloved, building yourselves up on your most holy faith, praying in the Holy Spirit, 21keep yourselves in the love of God, waiting anxiously for the mercy of our Lord Jesus Christ to eternal life. 22And have mercy on some, who are doubting; 23save others, snatching them out of the fire; and on some have mercy with fear, hating even the garment polluted by the flesh.

Jude 1:3: 3Beloved, while I was making every effort to write you about our common salvation, I felt the necessity to write to you appealing that you contend earnestly for the faith which was once for all handed down to the saints.

Romans 16:17: 17Now I urge you, brethren, keep your eye on those who cause dissensions and hindrances contrary to the teaching which you learned, and turn away from them.

2 John 1:10,11: 10If anyone comes to you and does not bring this teaching, (the teaching of Jesus Christ; author’s note) do not receive him into your house, and do not give him a greeting; 11for the one who gives him a greeting participates in his evil deeds.