“These two terms, grace and peace, constitute Christianity. Grace involves the remission of sins, peace, and a happy conscience. Sin is not canceled by lawful living, for no person is able to live up to the Law. The Law reveals guilt, fills the conscience with terror, and drives men to despair. Much less is sin taken away by man-invented endeavors. The fact is, the more a person seeks credit for himself by his own efforts, the deeper he goes into debt. Nothing can take away sin except the grace of God. In actual living, however, it is not so easy to persuade oneself that by grace alone, in opposition to every other means, we obtain the forgiveness of our sins and peace with God.” — Martin Luther

 

Perhaps John Newton said it best…

Amazing Grace!
How sweet the sound
That saved a wretch like me
I once was lost but now am found
Was blind but now I see!