How come you believe in a doctrine of Grace? Who wrote about it and then it became a doctrine? And obviously, it's a misused and misrepresentation of what this Person wrote.
I believe that Jesus fulfilled the law. His blood was taken into the Holy of Holies and put on the mercy seat and His blood is the fulfillment of the atoning blood talked about and described in the OT.
Because of what Jesus did the way into the Holy of Holies is opened and so I can enter in and place my petitions before the throne of grace. The doctrine of grace says clearly that Jesus blood fulfilled the requirement of the law.
This doesn't change the fact that sin is still sin, God hates sin, and you must be cleansed of all sins. You can't simply say "my bad", you have to in many cases pay restitution. But, the Lord gives you grace to do that.