In his narrative on the life and teaching of the Lord Jesus, Luke describes the conspiring of the chief priests, the teachers of the law, and the elders against Messiah. Their goal was to try to discredit the Lord before the crowds listening to His teaching and preaching in the courts of the Temple Mount. They mounted the next attack:
20Keeping a close watch on him, they sent spies, who pretended to be honest. They hoped to catch Jesus in something he said so that they might hand him over to the power and authority of the governor. 21So the spies questioned him: "Teacher, we know that you speak and teach what is right and that you do not show partiality but teach the way of God by following the truth. (Luke 20:20-21).
The priests and teachers of the law sent spies (v. 20) hoping that they could catch Him out by using His own words and teachings against Him. Jesus had silenced them once already and spoken a parable which focused on their plans to kill Him (Luke 20:1-19). Their response was to look “for a way to arrest Him immediately” (20:19). Why immediately? Their religious money-making schemes were threatened. Jesus had overthrown the tables of the moneychangers and stopped them selling in the Temple Courts. Those in power, the religious elite, could not give up; there was too much money, power, and authority at stake. They decided that they would try another attack on Jesus; this time, it would be on the issue of taxation imposed on Israel by the Roman authorities. If they could get Him to say something against paying the tax, they could tell the Roman governor that He was a rebel against the state and should be executed.
They assembled certain individuals that were good actors. Some of the leaders were sent to keep a close watch on Him, no doubt taking note of His every word. In verse 21, Luke calls them spies. They were sent to appeal to His pride by flattering Him, attempting to gain trust among His followers before asking their questions. (The word translated “pretended” (v. 20) in the NIV, comes from the Greek word hypokrinomai, which means to play the role of an impersonator or actor. We get the word hypocrite from the root of this word. The enemy masks his motives by using flattery to appeal to a man's pride. They were hoping that Jesus would not detect their true motives or see where they were going with their questions by inflating His ego. It was a classic misdirect! A man or woman can be blinded to the enemy's attack by his or her pride. Many a minister has passed the test of outright sin but fallen quickly to the sin of pride. CS Lewis wrote about this in his book, Mere Christianity:
If anyone thinks that Christians regard unchastity as the supreme vice, he is entirely wrong. The sins of the flesh are bad, but they are the least bad of all sins. All the worst pleasures are purely spiritual; The pleasure of putting other people in the wrong, of bossing and patronizing and spoiling sport, and backbiting; the pleasures of power, and of hatred. For there are two things inside me competing with the human self which I must try to become; they are the animal self, and the diabolical self; and the diabolical self is the worst of the two. That is why a cold, self-righteous prig (a person who demonstrates an exaggerated conformity or propriety) who goes regularly to church may be far nearer hell than a prostitute. But, of course, it’s better to be neither.
Pride is one of God's greatest enemies. Pride is what caused Satan to fall (Isaiah 14:12-17). If you would like to please your enemy, begin to admire yourself. Pride is so hard to see in ourselves but easy to see in others. God resists the proud but gives grace to the humble. There will always be grace issuing from our lives if we will seek the best for others rather than elevating self. Jesus never gave in to a spirit of pride for one minute. Christ took every opportunity to humble Himself and show us the way. Watch Him as He washed the dirty, grimy feet of the disciples. Watch Him as He touched the leprous. He would look for the lowest seat when He was invited to a meal. There was none humbler than the Lord Jesus. Be careful of the sin of pride. Keith Thomas
Shortened from the more complete study on Luke 20:20-47. Questions About Eternity.
 C. S. Lewis, Mere Christianity, (New York: Macmillan, 1986).