We’ve already established that discerning between truth and error is biblical. Consider what John, the Apostle of Love says:
1Jn 4:1 Beloved, believe not every spirit, but try the spirits whether they are of God: because many false prophets are gone out into the world.
Not every spirit is of God – because many false prophets have gone out into the world. In other words, we can’t just judge by a “feeling”. A false prophet preaches a false message. We must judge the content of the message to test the spirit. Sometimes we may be tempted to judge a message by whether it had an “anointing” meaning we have a sense or feeling of something Divine and mystical when we hear it. John warns the believers to test the spirits.
In the book of Acts, Luke tells us that the “noble mind” receives the word gladly, but searches the scriptures daily to prove it out. This implies a rejection of that which does not match scripture:
Act 17:11 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.
A believer who has God’s word in his heart should be listening to the speaker with the outward ear, but inwardly comparing it with the truth they know from the word. We must listen to God rather than man when we find a contradiction.
It is biblical and wise to not believe everything we hear but to hide from the danger represented by falsehood and error:
Pro 14:15 The simple believeth every word: but the prudent man looketh well to his going.
Pro 27:12 A prudent man foreseeth the evil, and hideth himself; but the simple pass on, and are punished.
Jesus warned that as the age drew to a close, one of the great signs would be people coming in His name – false prophets, deceiving many.
Mat 24:4 And Jesus answered and said unto them, Take heed that no man deceive you. For many shall come in my name, saying, I am Christ; and shall deceive many…
Mat 24:11 And many false prophets shall rise, and shall deceive many.
Mat 7:15 Beware of false prophets, which come to you in sheep's clothing, but inwardly they are ravening wolves.
Paul warned the church at Ephesus that wolves would enter the flock, and even people among them would rise up speaking error.
Act 20:29 For I know this, that after my departing shall grievous wolves enter in among you, not sparing the flock. Also of your own selves shall men arise, speaking perverse things, to draw away disciples after them. Therefore watch, and remember, that by the space of three years I ceased not to warn every one night and day with tears.
Not only is it biblical to discern that which differs from the truth, we must also speak. Jude wrote his letter to exhort the saints to earnestly contend for the faith which was once delivered unto the saints. He warned that false teachers were creeping into the church without anyone realizing it.
jud 1:3 Beloved, when I gave all diligence to write unto you of the common salvation, it was needful for me to write unto you, and exhort you that ye should earnestly contend for the faith which was once delivered unto the saints.
Jud 1:4 For there are certain men crept in unawares, who were before of old ordained to this condemnation, ungodly men, turning the grace of our God into lasciviousness, and denying the only Lord God, and our Lord Jesus Christ.
Much can be found in the Bible about the need to not only discern error but to contend for truth. Discerning the error is one thing, but when we speak up to contend for truth, we will encounter resistance.