Note 5 at Lu 18:10: None of us can ever be righteous in the sight of God through our own righteousness (Isa 64:6; Ro 3:10, and 23). Our actions benefit us in relationships with people and prevent Satan from having an opportunity against us (Ro 6:16 and 1Pe 5:8), but they cannot make us right (righteous) with God. We must trust in God and receive His gift of righteousness (Ro 5:17) completely on the basis of faith in what Christ did for us (Ro 4:2-16, 22-24, 5:15-21, 9:30-33, 10:1-13; Ga 3:8-9, 11-29; Php 3:9; etc.). This is the truth that this parable is presenting.

Real Pharisees lived impeccable moral lives (see note 10 at Mt 5:20), while publicans were despised for their collaboration with the Roman government and their thievery (see note 23 at Mt 5:46). It wasn't the Pharisee's actions that were wrong; what he put his faith in was his problem. His faith was in his own actions as the basis of justification with God instead of in a Savior. The publican's actions were wrong, but he threw himself totally on the mercy of God and looked to Him for salvation. His faith was counted to him as righteousness (Ro 4:3-5 and 22-24).