In the parable of the persistent widow, Jesus shows us why we should pray—God is not an unjust judge, but the righteous Father who loves his elect and will bring justice. In the parable of the Pharisee and the Tax Collector, Jesus shows us how we should pray—not with pride, comparing ourselves to others, but in humility, needy for God’s mercy. Putting the two together, Luke aims to show us that we both ought to pray and never lose heart and that there is a certain heart that knows how to pray, and a heart that doesn’t.