I've heard people say that justification means that God looks at me "just-as-if-I'd" always obeyed — somehow, because of Jesus' obedience, when God looks at me He sees only Jesus' obedience. That sounds very holy and theologically wonderful until you reflect on it a bit. It leaves this lurking suspicion that God may love Jesus, but He rejects the real me ... the sinning me. In this sense I am not only presenting a fake persona to other people around me in order to be accepted, I am instructed to present a fake persona to God in order to be accepted.
The message of the cross of Christ shows forth a much stronger grace.
It sees our sin.
I do not come wearing a fake Jesus mask. It is most liberating that while God may deal with me just as if I'd never sinned, he does not see a fake me. He sees and loves the weak and sinful me. My sins have not simply been forgotten or overlooked, and He does not simply pretend that they never happened. In Christ I have been definitively and authoritatively forgiven.
The cross acknowledges that I have truly sinned, and that God has seen it all the way to its root; there is no pretense whatsoever. He has loved me knowing the depth and persistence and richness and evil of my sin. The justice for my sins has actually been executed, and a strong vengeance and wrath has been delivered upon my choice to obey my selfish and harmful lusts. I don’t have to act like I am OK or pretend like I am righteous. Justice has truly been executed.
We have to be willing to face the fact that if the law is going to be fulfilled for us, if justice is to be upheld, it is not a matter of future obedience. We are tempted to think that the fulfillment of the law involves obedience from now on; we are often foolish enough to think that from here on we will be sufficiently successful at our righteousness. We want to promise that we have "repented".
You do not need reform, you need redemption. Faith says that the blood of Jesus satisfies justice for every little thing we do wrong, all the time. Faith says that I always feel inadequate because I really am inadequate, but that I am saved through His cross from all of these judgements that daily accuse me. The cross declares that the law, which speaks so powerfully to my conscience, has been fulfilled — not because I obeyed it, but because Jesus has more than sufficiently borne its penalty. ... It is not your reform which saves you. It is Christ who saves you.
The cross of Christ declares that law has been fulfilled on my behalf — it is indeed finished. I do not need to wear a fake Jesus mask for God to accept me; I am accepted and justified in Christ as myself.