False doctrine is very dangerous. It is designed by Satan to cause people to be lost. During His personal ministry Jesus warned of false doctrine a number of times. In Matthew 7:15 He says, "Beware of false prophets, who come to you in sheep’s clothing, but inwardly are ravenous wolves." False prophets have the appearance of being legitimate since they are wearing sheep’s clothing. Their purpose is to destroy our souls.
False doctrine is deceiving. We are warned in Ephesians 5:6, "Let no man deceive you with vain words." But how does false doctrine deceive? Romans 16:18 says, "by smooth and flattering speech deceive the hearts of the simple." Oh, it may sound good and impressive, but it is still false. The denominational world is filled with false doctrine, which is designed to cause people to be lost. It even creeps into the Lord’s church.
As long as the world lasts there will always be false doctrine taught. 2 Peter 2:1-2 says, "But there were also false prophets among the people, even as there will be false prophets among you, who will secretly bring in destructive heresies, even denying the Lord that bought them, and bring on themselves swift destruction. And many will follow their destructive ways, because of whom the way of truth will be blasphemed." Notice that false doctrine is brought in secretly in a way that people are not aware of it. As this destructive doctrine is taught, the truth of God's word is evil spoken of and belittled.
But how do we recognize false doctrine so we can protect ourselves against it? 1 John 4:1 says, "Beloved believe not every spirit, but test the spirits whether they be of God; because many false prophets have gone out into the world." We are told to test them just as the Bereans did in Acts 17:11, ‘They…searched the scriptures daily to find out whether these things were so." If we will only study God’s word daily so "That we should no longer be children tossed to and fro by every wind of doctrine, by the trickery of men, in the cunning craftiness of deceitful plotting" (Ephesians 4:14).