These verses are directly related to the previous verses on the wide gate and broad way. Here Jesus warns of false prophets.  From Jesus’ time till now they have existed and still exist today.  These are people who claim to be speaking about the things of God when, in fact, they are deceivers.  So, outwardly they appear to be like sheep, but inside they are ravenous wolves.  So how can we tell the difference? These wolves are people who have an extreme appetite or hunger for wealth and power.  Although they appear to be driven by Biblical teachings, they are really driven by greed, wealth, and power.  Many such wolves have been fooling naive believers with their false performances for generations, but eventually their true motives are revealed.

Jesus tells us that we can know them by their fruits.  Sometimes this gets a little tricky because they are very good at their sheepish disguise.  We must look for love not in their words or even in their deeds, for both can be imitated, but in their character (this is their real fruit). It is their character that is faulty because it is like bad fruit from a bad tree.  Even if it looks good, it is rotten to the core.  Rest assured that their reward will be justly deserved for all the deception that they have spread.

2 Peter 2:3 (ASV)
³  And in covetousness shall they with feigned (false) words make merchandise of you: whose sentence now from of old lingereth not, and their destruction slumbereth not.

The King James and American Standard Version are closest to the proper Greek interpretation of this verse in Peter.  We can see the fulfillment taking place today where churches are concerned more with the production of their service than its content.  Believers have been turned into merchandise.  Making money off the Word of God in books, movies, and speaking engagements have priority over the real teachings of Jesus.  Let us remember how much Jesus charged for his teaching—nothing!  As a matter of fact, Jesus paid the ultimate price for us to listen—his death on a cross.  But over the years of my experience I realize that this is all that they have.  They do not have any real understanding of Jesus and therefore can’t teach what they themselves do not know.  They would be far better to be quiet sitting in the pews listening than to be preaching from the pulpit.

2 Corinthians 11:13-15 (KJV)
¹³  For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ.
¹⁴  And no marvel; for Satan himself is transformed into an angel of light.
¹⁵  Therefore it is no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works.

Paul warns us as he warned the Corinthians to be careful of appearances.  Many false prophets will appear to be apostles of Christ even to the point of looking like angels of righteousness.  It is one thing to preach about righteousness and another to be righteous. But God will not be fooled by them and they will suffer a righteous judgment by their own words.