1 Thessalonians 5:21

To the law and to the testimony: if they speak not according to this word, it is because there is no light in them.

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? Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit. A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit. Every tree that bringeth not forth good fruit is hewn down, and cast into the fire. Wherefore by their fruits ye shall know them.

And when he had called all the people unto him, he said unto them, Hearken unto me every one of you, and understand: There is nothing from without a man, that entering into him can defile him: but the things which come out of him, those are they that defile the man. If any man have ears to hear, let him hear.

Yea, and why even of yourselves judge ye not what is right?

These were more noble than those in Thessalonica, in that they received the word with all readiness of mind, and searched the scriptures daily, whether those things were so.

And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.