It is so easy for me, having been reared in a Christian home and being a "good" girl my entire life, to rest on the laurels of that "goodness" and not really consider the depths of sin actually present in my life. Any "goodness" in my life, or anyone else's life, is only the Holy Spirit holding back the effects of sin. It is not due to any inherent righteousness within me.
Paul makes that so clear in Romans. After narrowing to his thesis in chapter 1, verse 17, he lets us know that vile sin separates us from God.
In chapter 2, he then makes it clear that no one is exempt, not even those whose sins may not be so "vile."
In the third chapter he lets the Jews know that they are not exempt either unless they are walking by faith in Jesus Christ.
In the fourth chapter, he lets us know that Abraham was not justified by being the father of Israel, but only by his faith.
The only way I can truly understand the huge sacrifice that Christ made for me is by first seeing the depths of my human depravity and the totality of my inability to come to him. And then I can start to see just how much His gift did to rescue me.