How does the parable of the Pharisee and publican teach about righteousness?

In the parable of the Pharisee and the publican (Luke 18:9-14), Jesus contrasts two approaches to righteousness. The Pharisee, representing self-righteousness, trusts in his own works and looks down on others, while the publican, aware of his sinfulness, humbly seeks God's mercy. This parable illustrates the historic Reformed teaching that righteousness before God is not based on our efforts or merits but on God's grace alone. The publican's acknowledgment of his sin and plea for mercy serve as vital reminders that it is through faith in God's provision of grace that one acquires true righteousness. This understanding disrupts the notion that human effort can secure justification, emphasizing that it is ultimately God who justifies the sinner through Christ.