Luke:18.9
To some who were confident of their own righteousness and looked down on everybody else, Jesus told this parable:
“Two men went up to the temple to pray, one a Pharisee and the other a tax collector.
The Pharisee stood up and prayed about himself: ‘God, I thank you that I am not like other men– robbers, evildoers, adulterers– or even like this tax collector.
I fast twice a week and give a tenth of all I get.’
“But the tax collector stood at a distance. He would not even look up to heaven, but beat his breast and said, ‘God, have mercy on me, a sinner.’
“I tell you that this man, rather than the other, went home justified before God. For everyone who exalts himself will be humbled, and he who humbles himself will be exalted.”

Pharisees are a sect of Jew that oblige strictly to laws, both written and oral, passed down by traditions. They believe that one is righteous only when they strictly observe the law and all they look for is the physical appearance and acts.

That’s why we find the pharisee boasting to God about how he follows the law. He made the prayer about himself and clearly didn’t need God’s mercy.

Unlike the Pharisee, the publican who did not follow the law was able to acknowledge God as one who has mercy and forgives.

His prayer made use of God’s mercy, it showed how much he needed God and was very sincere. He went to God as someone who needed to be saved.

The tax collector was justified because he pleaded for the mercy of God. We need to know this, it is only by the mercies of God that we are who we are.