Wow God!

Whisper of God
Now to the one who works, wages are not credited as a gift but as an obligation. However, to the one who does not work but trusts God who justifies the ungodly, their faith is credited as righteousness.
Romans 4:4-5 NIV

Observation
Paul uses Abraham to show that we are justified by faith and not as a result of what we do as works of righteousness before God. Righteousness was credited to Abraham because he believed God and not because he was circumcised.
In chapter 2 Paul established that the "work" of circumcision means nothing outwardly unless it is accompanied by a circumcision of the heart. The Holy Spirit transforms our hearts by faith and not as a result of our works.
Abraham believed God - period. He knew that the promise God gave for a son was humanly impossible; he was nearly 100 years old and Sarah's womb at 90 was still barren and dead. But because He believed God the promised son Isaac was born. And righteousness was credited to Abraham not because of what he had done, but only because he chose to believe God.

Real Life Application
I cannot earn salvation or righteousness by what I do, or even what I don't do trying to obey God. It is all by faith.

Day's Prayer
Lord I confess that from time to time I am guilty of trying to do the right things in my own strength. In those times I fall flat on my face. I fail you not because I don't love you, but because somewhere in the back of my head I believe the lie that I have to earn your favor.
Forgive me for trying to earn your gift of salvation and righteousness by the works I try to do. Holy Spirit empower me with simple childlike faith to just believe. By faith you make me righteous, and by faith you will cause the righteousness of Jesus to be lived in me.
Wow God! You are so good to me; thank you for clothing me in righteousness I could never buy for myself.