Justification and Registration
A friend of mine had an imported car he hoped to get registered here in the U.S. He was told that while he might be able to get license plates, he'd never be able to legally drive the car since it didn't fundamentally meet American safety standards.
Most folks understand that Christ's death on the cross paid the price for our sins. But like my friend's imported car, there was something fundamentally wrong. We had to be made right in Christ before we would be legally OK with God.
Our justification in Christ not only takes care of our sins, it also transforms the sinner and gives us a new identity. It's as if my buddy's car could be completely recreated as an American model. The fact that your sins are forgiven because of Christ's is a wonderful thing. But let's not forget, we are completely new models-new creations-in Him.