Bible Verses About judging false teachers

Judge not, that ye be not judged.

Beware of false prophets, which come to you in sheep's clothing, but inwardly they are ravening wolves.

Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles?

Judge not according to the appearance, but judge righteous judgment.

Now I beseech you, brethren, mark them which cause divisions and offences contrary to the doctrine which ye have learned; and avoid them.

And have no fellowship with the unfruitful works of darkness, but rather reprove them.

Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the world, and not after Christ.

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;

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.

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

For many deceivers are entered into the world, who confess not that Jesus Christ is come in the flesh. This is a deceiver and an antichrist.

If there come any unto you, and bring not this doctrine, receive him not into your house, neither bid him God speed: