15 Beware of false prophets, which come to you in sheep's clothing, but inwardly they are ravening wolves. 16 Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles? 17 Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit. 18 A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit. 19 Every tree that bringeth not forth good fruit is hewn down, and cast into the fire. 20 Wherefore by their fruits ye shall know them. - Matthew 7:15-20

21 Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven. 22 Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works? 23 And then will I profess unto them, I never knew you: depart from me, ye that work iniquity. - Matthew 7:21-23

For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect. - Matthew 24:24

29 For I know this, that after my departing shall grievous wolves enter in among you, not sparing the flock. 30 Also of your own selves shall men arise, speaking perverse things, to draw away disciples after them. 31 Therefore watch, and remember, that by the space of three years I ceased not to warn every one night and day with tears. - Acts 20:29-31

17 Now I beseech you, brethren, mark them which cause divisions and offences contrary to the doctrine which ye have learned; and avoid them. 18 For they that are such serve not our Lord Jesus Christ, but their own belly; and by good words and fair speeches deceive the hearts of the simple. - Romans 16:17-18

13 For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ. 14 And no marvel; for Satan himself is transformed into an angel of light. 15 Therefore it is no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works. - 2 Corinthians 11:13-15

Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates? - 2 Corinthians 13:5

But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. - Galatians 1:8

Now the Spirit speaketh expressly, that in the latter times some shall depart from the faith, giving heed to seducing spirits, and doctrines of devils. - 1 Timothy 4:1

For the time will come when they will not endure sound doctrine; but after their own lusts shall they heap to themselves teachers, having itching ears; And they shall turn away their ears from the truth, and shall be turned unto fables. - 2 Timothy 4:3-4

But there were false prophets also among the people, even as there shall be false teachers among you, who privily shall bring in damnable heresies, even denying the Lord that bought them, and bring upon themselves swift destruction. And many shall follow their pernicious ways; by reason of whom the way of truth shall be evil spoken of. And through covetousness shall they with feigned words make merchandise of you: whose judgment now of a long time lingereth not, and their damnation slumbereth not. - 2 Peter 2:1-3

Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world. - 1 John 4:1