Doug Graham shares the lesson of this parable. To Jesus' Jewish audience this parable would have been shocking as the Pharisees were held in high esteem and tax collectors were shunned. Jesus was teaching that one could do all the religious activities and still behave in a way that's not pleasing to God. God cares about our hearts. When one becomes self-righteous it will lead to contempt for those Jesus died to save.
Pride/Arrogance/Conceit - this leads to feeling self-satisfied in one's own works rather than relying on God. Humility - an honest assessment of one's self, to see that we all need God. Grace - unmerited favour. The church is not for the religiously elite but a hospital for the spiritually poor.