Luke describes these men who are trying to trap Jesus as 'spies'.  As in all espionage operations, they were looking to find a way to achieve their objectives without being noticed or blamed.  Like many they started with flattery.  You will find the same technique in business, professional and educational conversations world-wide.  Flattering people is supposed to soften them up, making them believe that they are your friends ... so that they will let down their guard and expose their weakness ... and then they can be manipulated as you gain control.  The motivation is deceitful (Proverbs 26:24) but it has become a normal way for many to work - today's managers and directors are even sent on courses to learn these techniques of influencing people.  
 
Paradoxically, if the flattery was not at least partly true, it would not be effective to boost human vanity.  As the spies were addressing Jesus, all that they said was true, although they were so determined to catch Him out that they failed to realise how truly they had spoken.  Worse than that, although they spoke the truth, they did not believe what they were saying.  If they had, they would have asked Jesus to explain who He was and begged to become His disciples.

Everything Jesus said was true; everything He taught was right.  He did not favour the rich, the learned or the high religious figures of the day - neither did He despise women, the sick, lepers, Gentiles or the demonised ... everybody was treated fairly and equally according to their need and faith (James 2:1-4).  Yet the spies did not submit to Him.  It makes us realise how hard someone's heart can become even when God is next to them, yet they cannot see Him.

Knowing the truth is not the same as submitting to it (James 1:22-25)!  This is the daily challenge of every follower of Jesus, as temptations are fired at us.  We can be so obsessed in achieving our objectives that we fail to notice what Jesus wants to do.  We can even teach truth to others and ignore it ourselves.  In these ways we patronise the Lord, just using Him for our own ends.  Flattering the Lord without obeying Him is always malicious - it comes from a badly devious heart which will twist truth and displace goodness by evil.  Flattery is worse than lying (Proverbs 26:28).  Whatever sort of relationship we have with Jesus, it is worth asking the questions, ‘Am I serving Him or using Him?’, and, ‘Do I really believe what I say about Him?’... if so, ‘Am I practising what I believe?’ These are good 'spiritual audit' questions: the 'audit report' might well challenge us to change our lifestyle!