God be merciful to me a sinner. – Luke 18:13

Now, how suitable is this prayer for us! For is there a lip here present that this confession will not suit-“God be merciful to me a sinner?” Do you say,-“the prayer will suit the harlot, when, after a life of sin, rottenness is in her bones and she is dying in despair-that prayer suits her lips?” Ay, but my friend, it will suit thy lips and mine too. If thou knowest thine heart, and I know mine, the prayer that will suit her will suit us also. You have never committed the sins which the Pharisee disowned; you have neither been extortionate, nor unjust, nor an adulterer; you have never been even as the publican, but nevertheless the word “sinner” will still apply to you; and you will feel it to be so if you are in a right condition. Remember how much you have sinned against light. It is true the harlot hath sinned more openly than you, but had she such light as you have had? Do you think she had such an early education and such training as you have received? Did she ever receive such checkings of conscience and such guardings of providence, as those which have watched over your career? This much I must confess for myself- I do, and must feel a peculiar heinousness in my own sin, for I sin against light, against conscience, and more, against the love of God received, and against the mercy of God promised. Come forward, thou greatest among saints, and answer this question,-dost not this prayer suit thee? I hear thee answer, without one moment’s pause-“Ay, it suits me now; and until I die, my quivering lips must often repeat the petition, ‘Lord have mercy upon me a sinner.’ ” Men and brethren, I beseech you use this prayer to-day, for it must suit you all.

Come. I beseech thee, just as thou art-thy nakedness is thy only claim on heaven’s wardrobe; thy hunger is thy only claim on heaven’s granaries, thy poverty is thy only claim on heaven’s eternal riches. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0216.cfm