This verse is well known and even quoted by people outside the Christian faith.  It has a 'ring of rightness' about it.  This 'Golden Rule' (as some people call it) is a practical test of righteousness: would we like others to do good to us, and would we want to hear kind words from the lips of other people?  Then, we should behave like that towards them.  

The sentence begins with a Greek word translated as ‘So’ or ‘Therefore’.  That means that Jesus’ statement is related to what He has previously said about our parental instinct to give good gifts to our children, and Father God’s unchanging character expressed by His good and perfect gifts to those who trust Him (Matthew 7:7-11; James 1:17).  Because only good things come to us from God, what should come from us to others?  Surely only good things!  

At the lowest level of ethics, if we want other people to behave well towards us, we should treat them in the same way – all the time.  However, trying to do good with an unrighteous heart will always lead to religious hypocrisy.  That is why Jesus said in Matthew 5:20, "For I tell you that unless your righteousness surpasses that of the Pharisees and the teachers of the law, you will certainly not enter the kingdom of heaven."  The Pharisees wanted to look good, but they failed to be righteous 'in everything' because they had not asked God for a new heart (Jeremiah 29:13; Joel 2:12).  Their religious pride prevented them being hungry for the right kind of heart.

Consistent righteous living is impossible without a heart which is fixed on the Lord, desiring what He desires and being willing to obey whatever the cost.  In comparison, religious activities are easy: presenting our rehearsed devotions to admiring people.  The Lord is not looking on the outside, but the inside (1 Samuel 16:7).  And yet what is inside our hearts comes to the surface in the unprepared and stressful times (Matthew 15:19).  So although the 'Golden Rule' of this verse is an excellent test of our hearts, we cannot change our hearts by manipulating our behaviour.  Firstly we need to seek the Lord with all our heart, and then He will enable us to live in a way which pleases Him and our family and neighbours and work colleagues.