When are you good to God?

Luther:

Everyone thinks that God finds you good when you live a good life and so have a good conscience. In the past I did too, but now I dispute this nonsense. Because if it were so, why did Christ die? When we try to get a clear conscience by our own efforts, what did He die for then? Learn to know Christ again as the Crucified and despair of yourself: only then you shall find true peace. Say to Him: ‘You, Lord Jesus, You are my righteousness and I am your sin. What I was, You took upon You and You gave me what I was not.