Some of the 'teachers of the law' may have been Pharisees, as they commended Jesus’ teaching about the resurrection - which had been opposed by the Sadducees (Luke 20:39).  Some may have been scribes.  Originally, scribes were all Levites (priests) who transcribed the Old Testament text from one generation to another.  But by Jesus' day they were devout educated men who became religious teachers and religious lawyers acting as the legal advisors to magistrates, always ready to accuse people who disobeyed the commandments.  Yet, at the same time, they pretended that they were perfect or above the law.  

These men enjoyed an honoured place in society and the synagogues, but Jesus had some very hard words for them.  He gave a public warning that these men were not the protectors of truth but were spiritually dangerous.  They dressed in expensive clothes, and behaved in a vain and arrogant manner, demanding to be seen as VIPs in the synagogues and at civic receptions.  

Purporting to be the authorised interpreters of God’s Word, they did not live in a godly way.  They were also greedy for money.  Under the guise of encouraging more offerings for God's work, they also got money for themselves ... and the easiest targets were widows.  Their long and eloquent prayers had the semblance of godliness (Matthew 6:5), but the teachers of the law had no personal experience of God’s transforming power in their own lives (2 Timothy 3:5).  Jesus’ condemnation was strong, "These men will be punished most severely"!

They fell to the most basic temptations: vanity, pride and greed.  John puts it like this, "Do not love the world or anything in the world. If anyone loves the world, love for the Father is not in them.  For everything in the world – the lust of the flesh, the lust of the eyes, and the pride of life – comes not from the Father but from the world.  The world and its desires pass away, but whoever does the will of God lives for ever." (1 John 2:15-17).  It is an age-old set of spiritual problems which can engulf any believer, church or mission unless our eyes are fixed on Jesus Christ.  If you have fallen in any of these areas, repent!  And if you think you have not fallen, 1 Corinthians 10:12 says, "So, if you think you are standing firm, be careful that you don't fall!"  Hypocrisy (acting a part in a play) is easy to get into and difficult to escape.  But in Christ we can!