The Pharisee and the Tax Collector
Two men went up to the temple to pray, one a Pharisee and the other a tax collector. The Pharisee, standing by himself, was praying thus, 'God, I thank you that I am not like other people: thieves, rogues, adulterers, or even like this tax collector. I fast twice a week; I give a tenth of all my income.' But the tax collector, standing far off, would not even lift up his eyes to heaven but was beating his breast and saying, 'God, be merciful to me, a sinner!' I tell you, this man went down to his home justified rather than the other, for all who exalt themselves will be humbled, but all who humble themselves will be exalted.
Luke 18:10-14
Luke says Jesus aimed this at people who trusted in themselves that they were righteous and despised others. Tax collectors were considered traitors, the least likely heroes imaginable.
The Pharisee's prayer was a performance review of himself with God as the audience. The tax collector's seven words were the only prayer that worked. Heaven is entered by honesty, not by comparison.
Notice when your prayers start listing credentials or measuring yourself against worse people. Trade the resume for the seven words: God be merciful to me a sinner. Pray them today and mean them.