The Pharisee and the Publican. We are not to look at others and measure them by our standards.
We don't see other person's heart and true worth.
The pharisee became the man he was because he was brought up looking down at lay people.
Tax collector was probably afflicted in his life. We are to comfort the afflicted.
So, every time we are successful in our purity and good deeds we should not think of ourselves as good because only God is good. Be truthful before God.