John 19:29-30 “Now there was set a vessel full of vinegar: and they filled a spunge with vinegar, and put it upon hyssop, and put it to his mouth.  When Jesus therefore had received the vinegar, he said, It is finished: and he bowed his head, and gave up the ghost.”  KJV

My woodstove has a big glass on the front, and it’s my favorite TV in the winter time.  I can have the hottest, most soot-filled fires in that box, and the glass turns so black and crusty that you’d think that there’s no way on God’s green earth that it could look or be clean ever again.
But with an old newspaper and vinegar-water, all of that crud comes off.  It makes the glass cleaner and shinier than a new penny. This makes me think of our Savior, when they put vinegar up to his mouth when he was thirsty (And to think it was our sin that caused him to thirst while he was giving us living waters), hanging on the cross, dying to cleanse our sin-sooty lives completely and to make us whole.  Everything that Jesus accomplished made it so that we could have a perfectly whole relationship with God…Period.
If I just focused on the crud of my stove glass, it would never get clean.  Same principle applies in that focusing on our sin doesn’t do any good whatsoever unless it leads us to utilize the real solution.  My stove glass can never make itself clean, and neither can we make ourselves clean.  
Jesus made us holy by his work. No matter how stained we are in the fires and trials of life, Christ finished work cleanses us completely by faith. You could say that faith is like the newspaper.  It absorbs every drop of the cleaner and applies it to our sin-stained life; past, present, and future. We became clean with the words, it…, is…., finished.