7 ways to spot a false Teacher

 Read 2 Peter 2.

Christianity has always been infiltrated by charlatans.  It remains one of the schemes of the devil to oppose the advancement of the kingdom of God.  They do not wear signs hanging around their necks stating, "I am a false teacher.  Do not listen to me."  Just the opposite is true.  They appear to be followers of Jesus and sound as if they are.  But, in truth, they are unbelievers, cloaked in religious garb and jargon, deceiving the unsuspecting.

The purpose of the writing of 2 Peter is to encourage believers to "grow in the grace and knowledge of our Lord and Savior Jesus Christ."  The prophet Hosea recorded the LORD's contention with His people: "My people are destroyed for lack of knowledge..." (Hosea 4:6).  In other words, they did not know the truth of what God had said.  Even church attenders are taken in by false teaching because they are not growing in their knowledge of God's word.  As a result they are immature in their faith and are not able to discern the difference between truth and error. (Ephesians 4:14)

This chapter is filled with exact descriptors of false teachers.  It is important to note that no pastor or Bible teacher is without sin.  Occasionally, we may learn of a godly person who fell, overcome by some sin, and it became known.  Such a person is not who Peter has in mind here.  False teachers are those "who will secretly bring destructive heresies, even denying the Master who bought them" (v.1).  They are not followers of Christ but posers.  Jesus died for them, as He did for all (John 3:16), but they act as ministers for their own benefit. 
1. They are SUBTLE. (v.1)
"For such are false apostles, deceitful workmen, disguising themselves as apostles of Christ.  And no wonder, for even Satan disguises himself as an angel of light.  So, it is no surprise if his servants, also, disguise themselves as servants of righteousness." (2 Corinthians 11:13-15)
2. They are SENSUAL. (v.2)
Their teachings concerning immorality and marriage contradict what God's word clearly states.  They will dismiss the Bible's teaching concerning sexuality as either culturally irrelevant or as merely the human author's opinion.  This is done under the themes of acceptance and unity.  At the root is their own lust.
3. They are SALESMEN. (v.3)
The Greek word has to do with "an emporium".  They make merchandise of people for their own gain.  They equate godliness with prosperity and greed.
4. They are SELF-WILLED. (vv.10-13a)
Their words are presumptuous, arrogant, daring, and bold, even to the point of rebellion against authorities.  They reject any personal accountability for their theology, their finances, their behavior, their lifestyle, or their empty promises.
5. They are STAINS on the Body of Christ. (vv.13b-16)
Their misrepresentation of God's word and their sinful behaviors leave ugly marks on the ministry without shame.
6. They are SPEAKERS of empty promises. (vv.17-18)
They look good. They sound good.  They tell great stories.  They make people laugh.  They move them emotionally.  But what is the spiritual outcome?  Consistently, these liars give false, earthly hope to discouraged hearers based upon their own clever words.  Meanwhile, they omit the eternal hope that comes through faith alone in Christ.  Positive thinking and temporal prosperity will never relieve anyone of the awful burden of guilt for their sin.   
7. They are SLAVES to sin. (v.19)
These phonies preach freedom of one kind or another, when they are actually in bondage to their own passions.

Our defense against being deceived by any false teaching is to personally read, study, and be taught the truth of the Scriptures.  There is no substitute.  It is the foundation to growing in grace.