This episode (Lk 18: 9-14) which is unique to Luke brings in specifically Lukan part of the travel narrative (Lk 9: 51 – 18: 14) to an end. It is significant that Luke has made prayer – one of his favourite themes – the topic of this final episode. It is an example – story like the parable of the Good Samaritan (Lk 10: 30-37). In the light of Luke’s own introductory verse (Lk 18: 9), which states the purpose of the parable, its over-all thrust is related to the theme of the ‘gospel of the Outcast’ in chapter 15 of Luke. What shines through the story is God’s mercy for (those despised as) sinners (Lk 18: 1-13; Cf. 15: 30) who acknowledge humbly their unworthiness in the sight of God. Let us recall that in Lk 15, Jesus defended his association with the outcast of society (Lk 15: 1).
The previous parable (Lk 18: 1-8) contributed to the understanding of the final section of Jesus’ eschatological instruction: God will certainly vindicate his elect at the coming of the Son of Man. The present parable highlights the true condition by which the elect will be justified by God.
The danger of spiritual pride was very real in life of those who set themselves apart (Pharisees) from the ordinary people. However, we should not conclude that all Pharisees were guilty of it. The attempt at achieving righteousness before God by one’s own meritorious acts was a common enough feature in Jesus’ time. He did react to such pursuit. This parable conveys his attitude.
In prayer, the self-righteous Pharisee speaks about himself. He catalogues his meritorious deeds, at first negatively: that he does not have he vices which are common to other people. His boasting reaches a climax when he compares himself with ‘this tax collector’. Then he boasts positively by spelling out his merits which are in the form of works of supererogation, that is, by doing more than what the laws requires. Thus, even though the laws did not demand fasting twice a week he observed it (Cf. Lev 16: 29, 31); even though the laws required to tithe only the agricultural produce (Deut 14: 22-23) he was tithing on all forms of income (Lk 18: 12). In this way the Pharisee ‘justified’ himself before God; it is not God who ‘justifies’ him. He relies on himself and not on God for his righteousness.
The tax-collector stands in sharp contrast with the Pharisee. He humbly and contritely acknowledges his sinful condition or unworthiness before God. He relies on God’s mercy for his ‘justification’, which is his free gift. In this way he is found upright in the sight of God (Lk 18: 14a). Justification, the parable tells us, is not something to be achieved by one’s own efforts or by boasting about one’s good deeds.
Verse 14b (a ‘Q’ saying and a doublet found also in Lk 14: 11) directs the parable to all Christian disciples. These should learn from the tax-collector as to how to pray and should not rely on themselves for their justification.
Finally, this parable could be seen as Jesus’ defence of his attitude toward tax-collectors and sinners.