If someone is arrogant and self-indulgent or if their only language is ‘Me-talk’, we say they are ‘full of themselves’. There is no room in their perspective to value another being to the same extent. All of the attention is focused on self-evaluation and self-promotion.
In the matter of prayer, God has encountered many people of whom it can be said, they are ‘full of themselves’.
One man was full of himself and the other was empty.
Now, it is possible to be full of self with self-loathing and self-hatred, but this tax collector was neither. He was in fact, humble—empty enough to recognize his personal failures and the need for God’s mercy to make him right.
If we are to pray effectively, we must learn about emptying. Prayer is a dumping ground for everything that causes us to exalt ourselves. Prayer is not a shrine erected to self-hatred or the place to grovel in how sinful we are. It is humble self-assessment that brings us to the place of praying. Why else would the tax collector come before God but to acknowledge his greatest need of God’s mercy?