Jesus told a powerful and poinient parable one day to his disciples: 

"To some who were confident of their own righteousness and looked down on everybody else, Jesus told this parable: “Two men went up to the temple to pray, one a Pharisee and the other a tax collector. The Pharisee stood up and prayed about himself: ‘God, I thank you that I am not like other men—robbers, evildoers, adulterers—or even like this tax collector. I fast twice a week and give a tenth of all I get.’ But the tax collector stood at a distance. He would not even look up to heaven, but beat his breast and said, ‘God, have mercy on me, a sinner. I tell you that this man, rather than the other, went home justified before God. For everyone who exalts himself will be humbled, and he who humbles himself will be exalted.” (Luke 18:9-14, NIV).

This is a prayer all of us can pray, and is one of the important ways Jesus taught us to pray. Let me break it down a bit:

God - You are God. I am not. You are the creator and ruler over everything, including my life.

have mercy - I don't deserve your kindness and mercy, but would you freely give it to me? Your mercy is my only hope, for I have nothing that will save and release me besides your mercy.

on me - I'm not pointing fingers at everyone else. I'm pointing at me. Lord, I need help, I need grace, I don't know everything and I can't be good enough for you.

a sinner - I recognize my own depravity in light of Your greatness. There is nothing good in me. The work of Christ on the cross is my only hope. Save me from myself.

God, have mercy on me, a sinner.